Power transmission device, power transmission method, and power transmission system

ABSTRACT

A power transmission device includes a communication unit that transmits a power capability information transmission request via a communication channel and receives power capability information in response to the power capability information transmission request. The power transmission device also includes a processing unit that sets a parameter based on the power capability information. Further, the power transmission device includes a power transmission unit that wirelessly transmits power using the parameter. The communication unit transmits the power capability information transmission request before the power transmission unit wirelessly transmits the power.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation application of U.S.application Ser. No. 13/399,660 filed Feb. 17, 2012 and claims priorityfrom Japanese Priority Patent Application JP 2011-035046 filed in theJapan Patent Office on Feb. 21, 2011, the entire content of which ishereby incorporated by reference.

BACKGROUND

The present disclosure relates to a power transmission device, a powertransmission method, and a power transmission system.

Recently, power transmission systems capable of wirelessly transmittingpower between devices have come into use. Examples of theabove-described power transmission systems may be an electronic moneysystem, a ticket gate system of a transportation facility, a system forentrance/admission using an employee identification (ID) card or thelike, and an integrated chip (IC) card system using a reader/writer (anexample of a power transmission device) and an IC card (an example of apower reception device). As a technology for wirelessly transmitting alarger amount of power to a greater distance, a technology fortransmitting power, for example, by use of electric- or magnetic-fieldresonance, has also been developed.

Under these circumstances, a technology for wirelessly transmittingpower to a specific device has been developed. An example of atechnology for wirelessly transmitting power to a specific device bycontrolling directivity may be found in Japanese Patent ApplicationLaid-Open No. 2009-253762.

SUMMARY

In the technology of the related art for wirelessly transmitting powerto a specific device (hereinafter simply referred to as the “relatedart”), a power transmission device for transmitting power acquiresposition information indicating a position of a power reception deviceof a target to receive the transmitted power, and controls directivityof the power to be transmitted on the basis of the position information.Because the power transmission device to which the related art isapplied (hereinafter referred to as the “power transmission device ofthe related art”) transmits the power in a direction of a powerreception device, it is possible to further reduce the possibility ofother devices receiving the power, even when there are other devicescapable of receiving the power. Consequently, the power is likely to bewirelessly transmitted to a specific power reception device by use ofthe related art.

The power transmission device of the related art controls directivity ora transmission power level on the basis of reception level informationtransmitted from the power reception device to which the related art isapplied (hereinafter referred to as the “power reception device of therelated art”). Consequently, the power transmission device of therelated art is likely to transmit power to the power reception device ofthe related art efficiently to a certain extent.

However, it is possible to perform only ex post control because thepower transmission device of the related art controls the directivity orthe transmission power level on the basis of the reception levelinformation, transmitted from the power reception device of the relatedart, only after transmitting power (hereinafter referred to as “powertransmission”). Thus, there is a problem in that a loss of powertransmission (hereinafter referred to as “power transmission loss”)occurs when the power transmission device of the related art transmitsthe power to the power reception device of the related art.

It is desirable to provide a power transmission device, powertransmission method, and power transmission system, which are novel andimproved, and which are capable of reducing power transmission loss.

In a first embodiment, a power transmission device includes acommunication unit that transmits a power capability informationtransmission request via a communication channel and receives powercapability information in response to the power capability informationtransmission request, a processing unit configured to set a parameterbased on the power capability information, and a power transmission unitthat wirelessly transmits power using the parameter, wherein thecommunication unit transmits the power capability informationtransmission request before the power transmission unit wirelesslytransmits the power.

Preferably, the power capability information indicates a transmissiontype and a parameter type.

Preferably, the transmission type is defined by at least one of anelectromagnetic induction, electric waves, a magnetic-field resonance,and an electric-field resonance, and the power transmission unitwirelessly transmits the power using the at least one of theelectromagnetic induction, the electric waves, the magnetic-fieldresonance, and the electric-field resonance

Preferably, the parameter type is defined by at least one of afrequency, a voltage, and an azimuth angle, and the power transmissionunit wirelessly transmits the power using the at least one of thefrequency, the voltage, and the azimuth angle.

The power transmission device preferably includes a storage unit thatstores transmission power capability information, wherein the processingunit sets the parameter by comparing the parameter type indicated by thereceived power capability information and a parameter type indicated bythe transmission power capability information to add the parameter typeindicated by the received power capability information to a parametertype list.

Preferably, the processing unit is configured to calculate a pluralityof power transmission efficiencies for each of a plurality of parametersof the parameter type and to set a standard efficiency range based on amaximum power transmission efficiency of the plurality of powertransmission efficiencies.

Preferably, the communication channel is encrypted.

Preferably, the communication unit receives first power reception amountinformation for the parameter after transmitting the power, and theprocessing unit is configured to calculate a first power transmissionefficiency based on the first power reception amount information andcauses the power transmission unit not to transmit the power if thefirst power transmission efficiency is less than a predetermined value.

Preferably, the communication unit receives first power reception amountinformation for the parameter after transmitting the power, and theprocessing unit is configured to calculate a second power transmissionefficiency based on the first power reception amount information and togenerate parameter information excluding the parameter if the secondpower transmission efficiency is less than a predetermined value.

Preferably, if the communication unit receives additional first powerreception amount information for the parameter, the processing unitcalculates an additional second power transmission efficiency based onthe additional first power reception amount information, and, if theadditional second power transmission efficiency is less than thepredetermined value a predetermined number of times in a predeterminedperiod corresponding to the first power reception amount information andthe additional first power reception amount information, the processingunit excludes the parameter from the parameter information.

Preferably, the processing unit periodically or aperiodically includesthe parameter in the parameter information after the processing unit hasexcluded the parameter from the parameter information.

Preferably, the parameter does not exceed a power reception capabilityindicated by the power capability information, the communication unittransmits parameter information, the communication unit receives secondpower reception amount information after the power transmission unitwirelessly transmits the power, and the processing unit is configured tocalculate a plurality of third power transmission efficiencies of aplurality of parameters based on the second power reception amountinformation, to set a standard range based on the plurality of thirdpower transmission efficiencies, and to exclude one of the plurality ofparameters from the parameter information if the third powertransmission efficiency of the one of the plurality of parameters isoutside the standard range.

Preferably, the processing unit is configured to calculate a powertransmission unit price corresponding to the standard range, thecommunication unit transmits information indicating the powertransmission unit price, and the power transmission unit wirelesslytransmits the power using the parameter if the communication unitreceives a power transmission start request in response to theinformation indicating the power transmission unit price.

Preferably, if the third power transmission efficiency of the one of theplurality of parameters is outside the standard range, the powertransmission unit stops wirelessly transmitting the power.

Preferably, the communication unit transmits or receives connectioninformation for forming the communication channel via a non-contactcommunication using a carrier of a predetermined frequency.

Preferably, the communication unit transmits the power capabilityinformation transmission request via the non-contact communication, thecommunication unit receives the power capability information via thenon-contact communication, and the parameter does not exceed a powerreception capability indicated by the power capability information.

Preferably, the processing unit is configured to generate parameterinformation indicating the parameter, based on parameter candidates ofthe power, corresponding to an environment where the power istransmitted, set on the basis of the power capability information.

In a second embodiment, a power transmission method includestransmitting a power capability information transmission request via acommunication channel, receiving power capability information inresponse to the power capability information transmission request,setting a parameter based on the power capability information, andwirelessly transmitting power using the parameter, wherein thetransmitting the power capability information transmission request isperformed before the wirelessly transmitting the power.

In a third embodiment, a program causes a computer to executetransmitting a power capability information transmission request via acommunication channel, receiving power capability information inresponse to the power capability information transmission request,setting a parameter based on the power capability information, andwirelessly transmitting power using the parameter, wherein thetransmitting the power capability information transmission request isperformed before the wirelessly transmitting the power.

In a fourth embodiment, a power reception device includes a storage unitthat stores power capability information, a communication unit thatreceives a power capability information transmission request via acommunication channel, transmits the power capability information inresponse to the power capability information transmission request, andreceives parameter information based on the power capabilityinformation, and a power reception unit that wirelessly receives powerusing a parameter indicated by the parameter information, wherein thecommunication unit receives the power capability informationtransmission request before the power reception unit wirelessly receivesthe power.

According to the embodiments of the present disclosure described above,it is possible to reduce a power transmission loss.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an explanatory diagram illustrating a problem occurring inwireless power transmission in which power is wirelessly transmitted;

FIG. 2 is an explanatory diagram illustrating a problem occurring inwireless power transmission in which power is wirelessly transmitted;

FIG. 3 is an explanatory diagram showing a first example of acommunication channel establishment process in a power transmissionsystem according to an embodiment;

FIG. 4 is an explanatory diagram showing an example of power capabilityinformation according to an embodiment;

FIG. 5 is an explanatory diagram illustrating a first power transmissiontype according to an embodiment;

FIG. 6 is an explanatory diagram illustrating a second powertransmission type according to an embodiment;

FIG. 7 is an explanatory diagram also illustrating the second powertransmission type according to an embodiment;

FIG. 8 is an explanatory diagram illustrating a third power transmissiontype according to an embodiment;

FIG. 9 is an explanatory diagram illustrating a fourth powertransmission type according to an embodiment;

FIG. 10 is an explanatory diagram showing a second example of thecommunication channel establishment process in the power transmissionsystem according to an embodiment;

FIG. 11 is an explanatory diagram showing another example of powercapability information according to an embodiment;

FIG. 12 is a flowchart showing an example of an arbitration processaccording to an embodiment;

FIG. 13 is an explanatory diagram illustrating a method of determining apower transmission type in the arbitration process according to anembodiment;

FIG. 14 is an explanatory diagram illustrating a method of determining aparameter type in the arbitration process according to an embodiment;

FIG. 15 is a flowchart showing an example of a calibration process in apower transmission device according to an embodiment;

FIG. 16 is an explanatory diagram illustrating a process of specifying aparameter having a maximum efficiency value in a type of a parameter ofpower in the calibration process of the power transmission deviceaccording to an embodiment;

FIG. 17 is an explanatory diagram illustrating a process of setting astandard range of power transmission efficiency in a type of a parameterof power in the calibration process of the power transmission deviceaccording to an embodiment;

FIG. 18 is an explanatory diagram showing an example of a display screenpresented to a user in the calibration process of the power transmissiondevice according to an embodiment;

FIG. 19 is an explanatory diagram showing another example of the displayscreen presented to the user in the calibration process of the powertransmission device according to an embodiment;

FIG. 20 is an explanatory diagram showing an example of power parametersrecorded in a blacklist in the calibration process of the powertransmission device according to an embodiment;

FIG. 21 is an explanatory diagram showing an example of a powertransmission process in the power transmission system according to anembodiment;

FIG. 22 is an explanatory diagram showing an example of parameterinformation to be transmitted by the power transmission device accordingto an embodiment;

FIG. 23 is an explanatory diagram showing another example of theparameter information to be transmitted by the power transmission deviceaccording to an embodiment;

FIG. 24 is an explanatory diagram showing an example of a packet to betransmitted when a power reception device makes a response in responseto a receipt of the parameter information according to an embodiment;

FIG. 25 is an explanatory diagram showing an example of powertransmitted by the power transmission device on the basis of theparameter information according to an embodiment;

FIG. 26 is an explanatory diagram showing an example of powertransmitted by the power transmission device on the basis of theparameter information according to an embodiment;

FIG. 27 is an explanatory diagram showing an example of powertransmitted by the power transmission device on the basis of theparameter information according to an embodiment;

FIG. 28 is an explanatory diagram showing another example of powertransmitted by the power transmission device on the basis of theparameter information according to an embodiment;

FIG. 29 is an explanatory diagram showing another example of powertransmitted by the power transmission device on the basis of theparameter information according to an embodiment;

FIG. 30 is an explanatory diagram showing another example of powertransmitted by the power transmission device on the basis of theparameter information according to an embodiment;

FIG. 31 is an explanatory diagram showing an example of a powerreception report to be transmitted by the power reception deviceaccording to an embodiment;

FIG. 32 is an explanatory diagram showing an example of a packet to betransmitted when the power transmission device makes a response inresponse to a receipt of the power reception report according to anembodiment;

FIG. 33 is a flowchart showing an example of the power transmissionprocess of the power transmission device according to an embodiment;

FIG. 34 is a flowchart showing an example of a parameter setting processof the power transmission device according to an embodiment;

FIG. 35 is an explanatory diagram showing an example of a conversiontable used by the power transmission device to derive a parametercorresponding to a certain parameter type according to an embodiment;

FIG. 36 is a flowchart showing another example of the parameter settingprocess of the power transmission device according to an embodiment;

FIG. 37 is an explanatory diagram showing another example of theconversion table used by the power transmission device to derive aparameter corresponding to a certain parameter type according to anembodiment;

FIG. 38 is a block diagram showing an example of configurations of thepower transmission device and the power reception device constitutingthe power transmission system according to an embodiment;

FIG. 39 is an explanatory diagram showing an example of a hardwareconfiguration of the power transmission device according to anembodiment; and

FIG. 40 is an explanatory diagram showing an example of a hardwareconfiguration of the power reception device according to an embodiment.

DETAILED DESCRIPTION

Hereinafter, preferred embodiments of the present disclosure will bedescribed in detail with reference to the appended drawings. Note that,in this specification and the appended drawings, structural elementsthat have substantially the same function and structure are denoted withthe same reference numerals, and repeated explanation of thesestructural elements is omitted.

Hereinafter, description will be given in the following order.

1. Approach According to One Embodiment 2. Power Transmission SystemAccording to One Embodiment 3. Program According to One Embodiment(Approach According to One Embodiment)

Before the description of a configuration of the power transmissionsystem (which may hereinafter be referred to as a power transmissionsystem 1000) according to this embodiment, a power transmission approachaccording to this embodiment will be described. A process related to thepower transmission approach according to this embodiment to be describedlater can be treated as a process related to a power transmission method(a method of transmitting power) according to this embodiment.

[Problems Occurring in Use of Related Art]

Before the description of the power transmission approach according tothis embodiment, problems occurring in wireless power transmission forwirelessly transmitting power will be more specifically described. FIGS.1 and 2 are explanatory diagrams illustrating problems occurring in awireless power transmission for wirelessly transmitting power. Here,FIG. 1 shows a use case of the wireless power transmission to a specificdevice (power reception device) of a target of power transmission, forexample, within a vehicle such as an electric train. FIG. 2 shows a usecase of the wireless power transmission from a table to a specificdevice (power reception device) of a target of power transmission placedon a table provided, for example, in a coffee shop or the like.

In the use case shown in FIG. 1, for example, as in the related art, thepower transmission device acquires position information indicating aposition of the power reception device and controls a directivity ofpower to be transmitted by the power transmission device on the basis ofthe position information, thereby transmitting power to the powerreception device. However, when there are devices (which may hereinafterbe referred to as “non-target devices of power transmission”) other thanthe power reception device in a power transmission range, the power isreceived by the non-target devices of the power transmission, so thatthe power to be received in the power reception device is reduced. Thatis, power corresponding to the reduction of power to be received becomesa power transmission loss.

Here, for example, the power transmission device of the related artcontrols directivity or a level of transmission power on the basis ofreception level information to be transmitted from the power receptiondevice of the related art after the power is transmitted as describedabove, and thereby transmits power so that the power reception device ofthe related art can receive the power equal to or greater than a certainfixed level. However, the power transmission loss is further increasedif the power transmission device transmits power by setting up the powertransmission level, for example, as in the power transmission device ofthe related art, when the power transmission loss occurs as describedabove.

Because the power transmission device of the related art can control thedirectivity, for example, it is possible to avoid non-target devices ofpower transmission from receiving power and reduce the powertransmission loss by controlling the directivity. However, because thepower transmission device of the related art controls the directivity onthe basis of the reception level information transmitted from the powerreception device of the related art, the control of the directivity inthe power transmission device of the related art is ex post facto. Thecontrol of the directivity in the power transmission device of therelated art gives no guarantee, in terms of whether directivity after achange is suitable for power transmission (for example, whether thepower transmission loss is less than a predetermined value, or thelike).

The power transmission loss is not expected to be reduced even when therelated art is applied to the transmission of power in the use caseshown in FIG. 1.

As in the use case shown in FIG. 2, the non-target devices of powertransmission are more likely to be included in a power transmissionrange even if the directivity of power to be transmitted as in therelated art is controlled when there are the power reception device andthe non-target devices of power transmission on the table that functionsas the power transmission device. Consequently, as in the use case shownin FIG. 1 described above, the power transmission loss is not expectedto be reduced even when the related art is applied to the use case shownin FIG. 2.

As described above, the power transmission loss is not expected to bereduced when power is wirelessly transmitted even when the related artis used.

[Overview of Power Transmission Approach]

In the power transmission system 1000, the power transmission device(which may hereinafter be referred to as the “power transmission device100”) according to this embodiment constituting the power transmissionsystem 1000 sets parameter candidates of power to be transmittedaccording to an environment where the power is transmitted before thepower is transmitted to the power reception device. The powertransmission device 100 reduces the power transmission loss bytransmitting power using any one parameter of the set parametercandidates of the power.

More specifically, before starting the transmission of power, the powertransmission device 100 transmits a power capability informationtransmission request to the power reception device (which mayhereinafter be referred to as the “power reception device 200”), whichis a target of the power transmission according to this embodiment,constituting the power transmission system 1000, using an encryptedcommunication channel (which may hereinafter be referred to as a “firstcommunication channel”). Here, the power capability informationtransmission request according to this embodiment is a type of commandfor causing a device receiving the power capability informationtransmission request to transmit power capability information indicatinga capability regarding the transmission/reception of power in thedevice. The power transmission device 100 sets a parameter, in which apower transmission efficiency equal to or greater than a certain fixedlevel can be acquired in an actual environment where power istransmitted, as a parameter candidate of the power among parameters ofthe power that does not exceed a power reception capability indicated bythe power capability information transmitted from the power receptiondevice 200 in response to the power capability information transmissionrequest.

The power transmission device 100 generates parameter informationindicating parameters of power to be sequentially transmitted in a powertransmission period for every power transmission period on the basis ofset parameter candidates of the power, and sequentially transmits thegenerated parameter information to the power reception device 200, whichis the target of the power transmission, by use of the firstcommunication channel. In each power transmission period, the powertransmission device 100 transmits the power by use of the parameters ofthe power indicated by the corresponding parameter information. Althoughexamples of the parameters of the power according to this embodiment maybe a frequency, a voltage, an azimuth angle, and the like, theparameters of the power according to this embodiment are not limited tothe above.

Hereinafter, the power transmission period in which the powertransmission is performed between the power transmission device 100 andthe power reception device 200 may be referred to as a “session,” and atransmission unit of power to be sequentially transmitted in the powertransmission period may be referred to as a “step.” That is, the stepaccording to this embodiment is a minimum unit of the power transmissionin the power transmission system 1000, and the session according to thisembodiment is a standard unit of the power transmission in the powertransmission system 1000 including a plurality of steps.

The power reception device 200 receives the parameter information viathe encrypted first communication channel. Consequently, even when thepower transmission device 100 transmits the power using any oneparameter among the parameter candidates of the power, the powerreception device 200 can efficiently receive the power transmitted onthe basis of the parameter indicated by the parameter information. Thus,because it is possible to further increase the power transmissionefficiency in the power transmission system 1000, the power transmissionloss can be reduced.

Because a non-target device of the power transmission does not receivepower on the basis of the parameter information as in the powerreception device 200, it is difficult to efficiently receive the powertransmitted from the power transmission device 100 even if it is in thepower transmission range. Consequently, the power transmission device100 transmits the power using any one parameter among the parametercandidates of the power, thereby further reducing unauthorized powerreception by the non-target device of the power transmission.

Therefore, the power transmission device 100 transmits the power to thepower reception device 200 using a parameter corresponding to anenvironment where the power is transmitted, so that a power transmissionsystem capable of reducing the power transmission loss is implemented.

The power transmission approach according to this embodiment is notlimited to the transmission of power using any one parameter among theset parameter candidates of the power by the power transmission device100. For example, the power transmission device 100 further calculates apower transmission efficiency (which may hereinafter be referred to as“first power transmission efficiency”) in a power transmission period inwhich the power has been transmitted, and stops the power transmissionif the calculated first power transmission efficiency is less than apredetermined value. Here, an example of the first power transmissionefficiency according to this embodiment may be a power transmissionefficiency in the entire power transmission period in which the powerhas been transmitted, or may be a power transmission efficiency in onlysome power transmission periods among power transmission periods inwhich the power has been transmitted. Hereinafter, an example in whichthe first power transmission efficiency according to this embodiment isthe power transmission efficiency in the entire power transmissionperiod in which the power has been transmitted will be described.

More specifically, the power transmission device 100 receives firstpower reception amount information, indicating a power reception amount(a measurement value measured in the power reception device 200) forevery parameter of the power indicated by the parameter information inthe power reception device 200, from the power reception device 200 viathe first communication channel. Here, the power transmission device 100can recognize the power transmission amount for every parameter, forexample, by measuring a transmission power for every parameter in eachpower transmission period. Consequently, the power transmission device100 can calculate the first power transmission efficiency, for example,by carrying out arithmetic operations of the following Equations 1 to 7.Hereinafter, the power transmission efficiency in each powertransmission period, that is, the power transmission efficiency in eachsession, may be referred to as “second power transmission efficiency.”

Here, E(i) denotes a power transmission efficiency in step i, Ps(i)denotes a power transmission amount in step i, and Pr(i) denotes a powerreception amount in step i. Esec(j) denotes a power transmissionefficiency in session j, that is, second power transmission efficiency,Pssec(j) denotes a power transmission amount in session j, and Prsec(j)denotes a power reception amount in session j. Eall denotes a firstpower transmission efficiency, Psall denotes an integrated powertransmission amount into which power transmission amounts are integratedin all power transmission periods in which power has been transmitted,and Prall denotes an integrated power reception amount into which powerreception amounts are integrated in all the power transmission periodsin which the power has been transmitted.

$\begin{matrix}{{E(i)} = {{\Pr (i)}/{{Ps}(i)}}} & \left( {{Equation}\mspace{14mu} 1} \right) \\{{{Esec}(j)} = {{{Prsec}(j)}/{{Pssec}(j)}}} & \left( {{Equation}\mspace{14mu} 2} \right) \\{{{Pssec}(j)} = {\sum\limits_{i = 1}^{M}\; {{Ps}(i)}}} & \left( {{Equation}\mspace{14mu} 3} \right) \\{{{Prsec}(j)} = {\sum\limits_{i = 1}^{M}\; {\Pr (i)}}} & \left( {{Equation}\mspace{14mu} 4} \right) \\{{Eall} = {{Prall}/{Psall}}} & \left( {{Equation}\mspace{14mu} 5} \right) \\{{Psall} = {\sum\limits_{j = 1}^{L}\; {{Pssec}(j)}}} & \left( {{Equation}\mspace{14mu} 6} \right) \\{{Prall} = {\sum\limits_{j = 1}^{L}\; {{Prsec}(j)}}} & \left( {{Equation}\mspace{14mu} 7} \right)\end{matrix}$

For example, when the first power transmission efficiency calculatedaccording to Equation 5 is less than a predetermined value, the powertransmission device 100 stops the transmission of the power. Here, anexample of the predetermined value to be used by the power transmissiondevice 100 to make a comparison with the first power transmissionefficiency may be a lower limit of a standard range of the powertransmission efficiency to be described later. A comparison between thefirst power transmission efficiency and the above-describedpredetermined value in the power transmission device 100 corresponds toa determination of whether or not the power transmission loss is greaterthan the predetermined value.

Here, if the calculated first power transmission efficiency (the powertransmission efficiency in the power transmission period in which thepower has been transmitted) is less than the predetermined value, forexample, it indicates that the power transmitted by the powertransmission device 100 is not received normally in the power receptiondevice 200. As a factor for which the power reception device 200 doesnot normally receive, for example, it is assumed that anenvironment-dependent power loss occurs due to an obstacle, atransmission distance, a collision of a frequency band, or the like,that power loss occurs due to dissipation of energy during wirelesstransmission, or that the power is received by a non-target device ofthe power transmission.

The power transmission device 100 can automatically stop the powertransmission even when the transmitted power is received by thenon-target device of the power transmission and the power transmitted bythe power transmission device 100 is not received normally in the powerreception device 200. Therefore, the power transmission device 100 stopsthe power transmission if the calculated first power transmissionefficiency (the power transmission efficiency in the power transmissionperiod in which the power has been transmitted) is less than thepredetermined value, thereby preventing the power from beingcontinuously transmitted in a state in which the power transmission lossis greater than the predetermined value. The power transmission device100 can prevent the power from being received by the non-target deviceof the power transmission by stopping the power transmission if thecalculated first power transmission efficiency is less than thepredetermined value.

[Example of Process Related to Power Transmission Approach]

Next, the process related to the power transmission approach accordingto this embodiment will be more specifically described. In the powertransmission system 1000, the process related to the above-describedpower transmission approach is implemented, for example, by a process(communication channel establishment process) of (1) to a process (powertransmission process) of (3) to be described later.

(1) Communication Channel Establishment Process

The power transmission device 100 and the power reception device 200establish a communication channel (first communication channel)encrypted to transmit/receive various information (data) such asparameter information. By performing the process of (1), the powertransmission device 100 and the power reception device 200 can transmitand receive various information (that is, information for implementingthe power transmission approach) such as parameter information via asecure communication channel. Here, an example of the firstcommunication channel according to this embodiment may be acommunication channel formed by a wireless communication using Instituteof Electrical and Electronics Engineers (IEEE) 802.15.1, a communicationchannel formed by a wireless communication (which may hereinafter bereferred to as “Wi-Fi”) using a wireless local area network (LAN) suchas IEEE 802.11b, a communication channel formed by a wirelesscommunication using IEEE 802.15.4, or the like. An example of the firstcommunication channel according to this embodiment may be based on awired communication by a LAN or the like.

(1) [1] First Example of Communication Channel Establishment Process

FIG. 3 is an explanatory diagram showing the first example of thecommunication channel establishment process in the power transmissionsystem 1000 according to this embodiment. Hereinafter, an example inwhich the first communication channel is a communication channel formedby a wireless communication using the wireless LAN such as IEEE 802.11bwill be described.

The power transmission device 100 and the power reception device 200perform a communication encryption process of forming the firstcommunication channel and encrypting the first communication channel(S100). More specifically, for example, a user of the power receptiondevice 200 selects the power transmission device 100 as a connectiondestination device from a search list of connection device candidates byoperating the power reception device 200, and inputs a one-time key(personal identification number (PIN)) for authentication. If theabove-described operation is performed by the user of the powerreception device 200, the power transmission device 100 and the powerreception device 200 perform an authentication and a communicationchannel encryption, for example, according to 8-way handshake and Wi-Fiprotected access 2 (WPA2) standards.

If the communication encryption process is performed in step S100, thepower transmission device 100 transmits a power capability informationtransmission request to the power reception device 200 (S102). Here, theprocess of step S102 is a process in which the power transmission device100 acquires power capability information from the power receptiondevice 200. For example, the power transmission device 100 determines apower transmission type and parameter candidates of the power to betransmitted to the power reception device 200 on the basis of powercapability information stored in a storage section of the powertransmission device itself (to be described later) and the powercapability information acquired from the power reception device 200. Ina process using the power capability information in the powertransmission device 100, a process (power-parameter candidatedetermination process) of (2) will be described later.

The power reception device 200 receiving the power capabilityinformation transmission request transmitted from the power transmissiondevice 100 in step S102 transmits, for example, the power capabilityinformation stored in the storage section of the power reception device200 (to be described later) to the power transmission device 100according to the receipt of the power capability informationtransmission request (S104).

FIG. 4 is an explanatory diagram showing an example of the powercapability information according to this embodiment. The powercapability information includes, for example, a header and a payload,and the payload has a flag (A of FIG. 4) indicating whether or not apower transmission/reception is possible, information (B of FIG. 4)indicating the number of corresponding power transmission types, andinformation of every corresponding power transmission type (C and D ofFIG. 4). An example of the information of every corresponding powertransmission type may be the number of parameters (E of FIG. 4),information of a type of parameter (F of FIG. 4) such as a frequency, avoltage, or an azimuth angle, information (G of FIG. 4) indicatingwhether a parameter is fixed or indicating a variation unit of theparameter, for example, such as 50 kHz, information (H of FIG. 4)indicating a possible range of a parameter such as 300 kHz to 600 kHz,or the like. Needless to say, the power capability information accordingto this embodiment is not limited to the example shown in FIG. 4.

[Power Transmission Type According to this Embodiment]

Here, the power transmission type according to this embodiment will bedescribed. Hereinafter, an example of the power transmission type willbe described focusing on a power transmission section (which mayhereinafter be referred to as a “power transmission section 106” to bedescribed later) included in the power transmission device 100 and apower reception section (which may hereinafter be referred to as a“power reception section 206” to be described later) included in thepower reception device 200.

[A] First Transmission Type: Power Transmission Using ElectromagneticInduction

FIG. 5 is an explanatory diagram illustrating the first powertransmission type according to this embodiment. Here, FIG. 5 shows aconfiguration example of the power transmission section 106 of the powertransmission device 100 and the power reception section 206 of the powerreception device 200 when power is transmitted using electromagneticinduction.

Referring to FIG. 5, the power transmission section 106 has analternating current (AC) power supply V, a capacitor C1, and an inductorL1. The power reception section 206 has an inductor L2, a capacitor C2,a capacitor C3, and a diode D1. In the power transmission section 106,an AC flows through the inductor L1 by the AC power supply V, and amagnetic flux is generated around the inductor L1. In the powerreception section 206, the diode D1 and the capacitor C3 rectify an ACflowing through the inductor L2 by the above-described magnetic flux,thereby obtaining a direct current (DC). Therefore, the power receptiondevice 200 to which the first transmission type is applied can receivepower transmitted from the power transmission device 100.

If the power transmission type using the electromagnetic induction asshown in FIG. 5 is used, it is possible to fluctuate and optimize apower transmission efficiency, for example, by varying the number ofturns or arrangement positions of the inductors L1 and L2.

[B] Second Transmission Type: Power Transmission Using Electric Waves(Microwaves)

FIG. 6 is an explanatory diagram illustrating the second powertransmission type according to this embodiment. Here, FIG. 6 shows aconfiguration example of the power reception section 206 of the powerreception device 200 that receives power by use of electric waves.

As shown in FIG. 6, the power reception section 206 has an antenna 10, aresonant circuit 12, a capacitor C4, a capacitor C5, a diode D2, a diodeD3, a capacitor C6, and a capacitor C7. Here, the resonant circuit 12includes, for example, a capacitor having a predetermined electrostaticcapacitance and an inductor having a predetermined inductance. In theabove-described configuration, if the antenna 10 receives electric wavestransmitted from the power transmission section 106 of the powertransmission device 100, an AC is supplied from the antenna 10 to theresonant circuit 12, and the resonant circuit 12 amplifies the AC byresonance. Furthermore, in the power reception section 206, a rectifyingcircuit including the diode D3 and the capacitor C6 rectifies theamplified AC, extracts a DC component, and obtains a DC. Therefore, thepower reception device 200 to which the second transmission type isapplied can receive power transmitted from the power transmission device100.

A configuration related to the second power transmission type accordingto this embodiment is not limited to the configuration shown in FIG. 6.FIG. 7 is an explanatory diagram also illustrating the second powertransmission type according to this embodiment. Here, FIG. 7 shows aconfiguration example of the power reception section 206 of the powerreception device 200 that receives power using the electric waves as inFIG. 6.

The power reception section 206 shown in FIG. 7 basically has the sameconfiguration as the power reception section 206 shown in FIG. 6, butthe antenna 10 shown in FIG. 6 is replaced with a plurality of antennas10A to 10M, a plurality of phase control circuits 14A to 14M, and adivider 16. FIG. 7 shows the case where a beam is formed, and the powerreception section 206 having the configuration shown in FIG. 7 canreceive beam-shaped electric waves.

[C] Third Transmission Type: Power Transmission Using Magnetic-FieldResonance

FIG. 8 is an explanatory diagram illustrating the third powertransmission type according to this embodiment. Here, FIG. 8 shows aconfiguration example of the power transmission section 106 of the powertransmission device 100 and the power reception section 206 of the powerreception device 200 when power is received using magnetic-fieldresonance.

The power transmission section 106 includes a resonant circuit having acapacitor C8 and an inductor L3 as shown in FIG. 8, and the resonantcircuit is connected, for example, to an AC power supply (not shown).The power reception section 206 has a capacitor C9 and an inductor L4.Here, the third transmission type uses the principle of resonance inwhich a vibration added to one side is also transferred to the otherside when two vibrators each having a specific number of vibrations arearranged. Consequently, it is possible to optimize the transmissionefficiency by adjusting each electrostatic capacitance and eachinductance so that a resonant frequency of the capacitor C8 and theinductor L3 of the power transmission section 106 is more equal to aresonant frequency of the capacitor C9 and the inductor L4 of the powerreception section 206. The power reception device 200 to which the thirdtransmission type is applied using the principle of resonance asdescribed above can receive power transmitted from the powertransmission device 100.

Here, the power transmission using the principle of resonance (the powertransmission by the third transmission type) as described above has ahigher power transmission efficiency than the power transmission usingthe electromagnetic induction (the power transmission by the firsttransmission type) or the power transmission using the electric waves(the power transmission by the second transmission type). The powerreception device 200 to which the third transmission type is applied canreceive about several kilowatts of power, for example, if a distancefrom the power transmission device 100 is several meters.

[D] Fourth Transmission Type: Power Transmission Using Electric-FieldResonance

FIG. 9 is an explanatory diagram illustrating the fourth powertransmission type according to this embodiment. Here, FIG. 9 shows aconfiguration example of the power transmission section 106 of the powertransmission device 100, and the power reception section 206 of thepower reception device 200, when power is received using electric-fieldresonance.

Like the above-described third transmission type, the fourthtransmission type uses the principle of resonance in which a vibrationadded to one side is also transferred to the other side when twovibrators each having a specific number of vibrations (a dielectricmaterial 18 and a dielectric material 20 in FIG. 9) are arranged.Consequently, it is possible to optimize the transmission efficiency byselecting each dielectric material so that a resonant frequency of thedielectric material 18 of the power transmission section 106 is moreequal to a resonant frequency of the dielectric material 20 of the powerreception section 206. Like the power reception device 200 to which thethird transmission type is applied, the power reception device 200 towhich the fourth transmission type is applied using the principle ofresonance as described above can receive power transmitted from thepower transmission device 100.

In the power transmission system 1000 according to this embodiment,power is transmitted from the power transmission device 100 to the powerreception device 200, for example, using the first to fourthtransmission types included in the above-described [A] to [D]. The powertransmission type in the power transmission system 1000 according tothis embodiment is not limited to the above-described first to fourthtransmission types, and it is possible to apply any transmission type inwhich power can be wirelessly transmitted.

The power transmission device 100 and the power reception device 200 canform the encrypted first communication channel, for example, byperforming the process shown in FIG. 3. The power transmission device100 acquires the power capability information, for example, includinginformation of a power transmission type corresponding to the powerreception device 200, from the power reception device 200 via the formedfirst communication channel.

The communication channel establishment process in the powertransmission system 1000 according to this embodiment is not limited tothe example shown in FIG. 3. For example, because a predeterminedconnection setup operation (for example, an operation of selecting adevice of a connection destination or an operation of inputting aone-time key (PIN) for authentication) performed by the user of thepower reception device 200 for starting a communication by the firstcommunication channel is unnecessary in the communication channelestablishment process shown in FIG. 3, it is possible to improve theconvenience of the user. More specifically, the power transmissiondevice 100 and the power reception device 200 transmit and receiveconnection information for starting the communication by the firstcommunication channel by performing a communication in a non-contacttype by a second communication channel different from the firstcommunication channel, thereby improving the convenience of the user.Here, the above-described second communication channel is formed by acommunication type in which the power transmission device 100 and thepower reception device 200 can perform one-to-one communication withouta particular connection setup by the user. The second communicationchannel according to this embodiment may be a communication channelformed by a near field communication (NFC) using a magnetic field(carrier) of a specific frequency, for example, such as 13.56 MHz, incommunication, a communication channel formed by an infraredcommunication in which an infrared ray is used in communication, or thelike.

Next, a process capable of further improving the convenience of the userbecause the above-described operation by the user for starting acommunication by the first communication channel is unnecessary will bedescribed as a second example of the communication channel establishmentprocess according to this embodiment.

[2] Second Example of Communication Channel Establishment Process

FIG. 10 is an explanatory diagram showing the second example of thecommunication channel establishment process in the power transmissionsystem 1000 according to this embodiment. Hereinafter, an example inwhich the first communication channel is formed by a wirelesscommunication using a wireless LAN such as IEEE 802.11b as in the firstexample shown in FIG. 3 will be described. Hereinafter, an example inwhich the second communication channel is a communication channel formedby NFC using a carrier of 13.56 MHz (an example of a predeterminedfrequency) will be described. In processes of the power transmissiondevice 100 and the power reception device 200 in FIG. 10, a process ofsteps S200 to S204 is related to a communication by the secondcommunication channel, and a process of step S206 is related to acommunication by the first communication channel.

A capture process is performed between the power transmission device 100and the power reception device 200 (S200). Here, the process of stepS200 is performed, for example, by a polling operation of capturing thepower reception device 200 after the power transmission device 100periodically or aperiodically transmits a specific carrier signal.

If the power reception device 200 is captured in step S200, the powertransmission device 100 transmits a power capability informationtransmission request to the power reception device 200 as in step S102of FIG. 3 (S202). Here, for example, connection information is furtherincluded in the power capability information transmission requesttransmitted in step S202. The power capability information transmissionrequest transmitted in step S202 may have, for example, a data structure(format) in which power capability information shown in FIG. 11 to bedescribed later is replaced with a command (substantial power capabilityinformation transmission request) for transmitting the power capabilityinformation.

The power reception device 200 receiving the power capabilityinformation transmission request transmitted from the power transmissiondevice 100 in step S202 transmits the power capability information tothe power transmission device 100 as in step S104 of FIG. 3 (S204).Here, if the second communication channel is formed by NFC, the secondcommunication channel is an encrypted secure communication channel. Ifthe communication by NFC is performed, a physical security is alsoimproved because the power transmission device 100 and the powerreception device 200 perform the communication at a distance of about 10cm. Consequently, the power transmission device 100 can securely acquirethe power capability information transmitted from the power receptiondevice 200 in step S204.

FIG. 11 is an explanatory diagram showing another example of the powercapability information according to this embodiment. Here, a datastructure in which the power capability information (J shown in FIG. 11)according to the embodiment shown in FIG. 4 is further added to ahandover message format (I shown in FIG. 11) defined in an NFC format isshown in FIG. 11. Needless to say, the data structure of the powercapability information according to this embodiment is not limited tothe example shown in FIG. 11.

The second example of the communication channel establishment process ofthe power transmission system 1000 according to this embodiment will bedescribed with reference back to FIG. 10. If the process of steps S202and S204 is performed, the power transmission device 100 and the powerreception device 200 perform a communication encryption process offorming and encrypting the first communication channel as in step S100of FIG. 3 (S206).

Here, if authentication information included in the connectioninformation shown in FIG. 11 is “OOB device password information” asdefined in Wi-Fi protected setup (WPS), the power transmission device100 and the power reception device 200 perform the 8-way handshakeprocess. The power transmission device 100 and the power receptiondevice 200 generate credential information in the 8-way handshakeprocess, and perform an authentication and a communication channelencryption according to a WPA2 standard. If the authenticationinformation included in the connection information shown in FIG. 11 isthe “credential information,” the power transmission device 100 and thepower reception device 200 perform the authentication and thecommunication channel encryption according to the WPA2 standard withoutperforming the 8-way handshake process. Consequently, the process shownin FIG. 10 is performed in which the user of the power reception device200 does not perform a predetermined connection setup operation (forexample, an operation of selecting a device of a connection destinationor an operation of inputting a one-time key (PIN) for authentication),so that the encrypted first communication channel is formed between thepower transmission device 100 and the power reception device 200.

For example, the process shown in FIG. 10 is performed, so that thepower transmission device 100 can acquire the power capabilityinformation from the power reception device 200 via the secondcommunication channel, and the power transmission device 100 and thepower reception device 200 can form the encrypted first communicationchannel without the above-described operation by the user for startingthe communication by the first communication channel.

In the power transmission system 1000, the encrypted first communicationchannel is established, for example, by the process related to the firstexample shown in FIG. 3 or the process related to the second exampleshown in FIG. 10. Consequently, the process of (1) is performed, so thata transmission/reception of various information (that is, informationfor implementing the power transmission approach) such as parameterinformation can be securely performed in the power transmission system1000.

The process (communication channel establishment process) of (1)according to this embodiment is not limited to the processes shown inFIGS. 3 and 10. Although the process in which the power transmissiondevice 100 acquires the power capability information from the powerreception device 200 is shown, for example, in FIGS. 3 and 10, the powertransmission device 100 may transmit the power capability information,for example, stored by the power transmission device itself, to thepower reception device 200. In the above-described case, the powercapability information is exchanged between the power transmissiondevice 100 and the power reception device 200.

(2) Power-Parameter Candidate Determination Process

If the encrypted first communication channel is formed by theabove-Described process (communication channel establishment process) of(1), the power transmission device 100 determines a power transmissiontype and parameter candidates of power to be transmitted to the powerreception device 200, for example, on the basis of the power capabilityinformation corresponding to the power transmission device itself andthe power capability information acquired from the power receptiondevice 200. More specifically, the power transmission device 100performs, for example, a process (arbitration process) of (2-1) and aprocess (calibration process) of (2-2) described below.

Although an example in which the power transmission device 100 performsthe process (arbitration process) of (2-1) will be described below, theprocess (power-parameter candidate determination process) of (2)according to this embodiment is not limited to the above. For example,if the power transmission device 100 and the power reception device 200exchange the power capability information in the above-described process(communication channel establishment process) of (1), both the powertransmission device 100 and the power reception device 200 may performthe process of (2-1), or the power reception device 200 may perform theprocess of (2-1). In the above-described case, the power transmissiondevice 100 performs the process (calibration process) of (2-2), forexample, by acquiring a result of the process of (2-1) in the powerreception device 200 from the power reception device 200.

(2-1) Arbitration Process

The power transmission device 100 determines a power transmission typeand a parameter type of power to be transmitted to the power receptiondevice 200, for example, on the basis of power capability informationcorresponding to the power transmission device itself stored in astorage section of the power transmission device itself (to be describedlater) and the power capability information acquired from the powerreception device 200. Here, because the power parameter type determinedin the process of (2-1) is determined on the basis of the powercapability information acquired from the power reception device 200, thepower transmission device 100 can determine parameter candidates ofpower that does not exceed a power reception capability of the powerreception device 200 in the process (calibration process) of (2-2) to bedescribed later.

[Specific Example of Arbitration Process]

FIG. 12 is a flowchart showing an example of the arbitration processaccording to this embodiment. Hereinafter, the process shown in FIG. 12,which is performed by the power transmission device 100, will bedescribed. In the above-described process (communication channelestablishment process) of (1) in FIG. 12, an example in which the powertransmission device 100 acquires the power capability information shownin FIG. 4 from the power reception device 200 and the power transmissiondevice 100 stores the power capability information shown in FIG. 4 willbe described.

The power transmission device 100 sets a value of m (where m is aninteger equal to or greater than 0) to m=0 (zero) (S300). Here, m is avalue for specifying a transmission type of the power transmissiondevice itself, and, for example, corresponds to a number indicating acorresponding transmission type included in a payload of the powercapability information shown in FIG. 4. The process of step S300corresponds to, for example, a process of setting to a minimum value anumber indicating the corresponding transmission type included in thepayload of the power capability information shown in FIG. 4.

If the process of step S300 is performed, the power transmission device100 determines whether or not the value of m is less than the number ofcorresponding transmission types (S302). Here, the power transmissiondevice 100 specifies the number of corresponding transmission types ofthe power transmission device itself, for example, by referring to thenumber of corresponding transmission types (B shown in FIG. 4) includedin the power capability information corresponding to the powertransmission device itself.

If the value of m is determined not to be less than the number ofcorresponding transmission types of the power transmission device itselfin step S302, it indicates that there is no transmission type consistentwith the transmission type corresponding to the power transmissiondevice itself and the transmission type corresponding to the powerreception device 200 in spite of a process performed for alltransmission types corresponding to the power transmission deviceitself. Consequently, the power transmission device 100 reports an error(S304) and ends the arbitration process. Here, the power transmissiondevice 100 visually reports the error to the user of the powertransmission device 100 and/or the user of the power reception device200 (may be collectively referred to hereinafter as the “user”), forexample, by causing a display device (for example, a display section tobe described later) included in the power transmission device 100, anexternal display device, or a display device included in the powerreception device 200 to display an error screen. The process of stepS304 in the power transmission device 100 is not limited to the above,and for example, the error may be audibly reported to the user bycausing an error sound (also including music) to be output from an audiooutput device included in the power transmission device 100, an externalaudio output device, or an audio output device included in the powerreception device 200.

If the value of m is determined to be less than the number ofcorresponding transmission types of the power transmission device itselfin step S302, the power transmission device 100 determines whether ornot there is the same transmission type as transmission type m in thereceived power capability information (S306).

If it is determined that there is not the same transmission type as thetransmission type m in the received power capability information in stepS306, the power transmission device 100 updates the value of m to m=m+1(S308). The power transmission device 100 iterates the process from stepS302.

If it is determined that there is the same transmission type as thetransmission type m in the received power capability information in stepS306, the power transmission device 100 sets the transmission type ofpower to be transmitted to the power reception device 200 to thetransmission type m (S310). Although not shown in FIG. 12, the powertransmission device 100 transmits information indicating thetransmission type m set in step S310 to the power reception device 200.

FIG. 13 is an explanatory diagram illustrating a method of determiningthe power transmission type in the arbitration process according to thisembodiment. Here, FIG. 13 shows an example of a power transmission typedetermined by the process of steps S300 to S310 shown in FIG. 12. FIG.13 shows the case where the transmission type corresponding to the powertransmission device 100 is the electromagnetic induction (theabove-described first transmission type) and the microwaves (theabove-described second transmission type), and the transmission typecorresponding to the power reception device 200 is the magnetic-fieldresonance (the above-described third transmission type), theelectric-field resonance (the above-described fourth transmission type),and the microwaves (the above-described second transmission type).

If the transmission types corresponding to the power transmission device100 and the power reception device 200 are the same as shown in FIG. 13,the power transmission device 100 sets the microwaves (theabove-described second transmission type), which is the consistenttransmission type, as the transmission type m by performing the processof steps S300 to S310 shown in FIG. 12.

Although the power transmission device 100 sets a first consistenttransmission type as the transmission type m if there are a plurality ofconsistent transmission types when the process of steps S300 to S310shown in FIG. 12 is performed, the process when there are the pluralityof consistent transmission types is not limited to the above. Forexample, the power transmission device 100 may set a transmission typehaving a highest priority among the consistent transmission types as thetransmission type m on the basis of a priority in a transmission typecorresponding to the power transmission device itself. For example, thepriority set in the above-described transmission type may be preset, ormay be set by the user.

The example of the arbitration process according to this embodiment willbe described with reference back to FIG. 12. If the transmission type isset in step S310, the power transmission device 100 sets a value of n(where n is an integer equal to or greater than 0) to n=0 (zero) (S312).Here, n is a value for specifying a corresponding parameter of thetransmission type m in the power transmission device itself, and, forexample, corresponds to a number indicating a parameter type (forexample, F shown in FIG. 4) included in a payload of the powercapability information shown in FIG. 4. The process of step S312corresponds to, for example, a process of setting to a minimum value anumber indicating the parameter type included in the payload of thepower capability information shown in FIG. 4.

If the process of step S312 is performed, the power transmission device100 determines whether or not the value of n is less than the number ofparameters of the power transmission device itself (S314). Here, thepower transmission device 100 specifies the number of correspondingparameters, for example, by referring to the number of correspondingparameters (E shown in FIG. 4) included in the power capabilityinformation corresponding to the power transmission device itself.

If the value of n is determined not to be less than the number ofcorresponding parameters of the power transmission device itself in stepS314, the power transmission device 100 ends the arbitration process bydetermining that the process is performed for all parameter typescorresponding to the power transmission device itself.

If the value of n is determined to be less than the number ofcorresponding parameters of the power transmission device itself in stepS314, the power transmission device 100 determines whether or not thereis a same parameter type as a parameter type n in the received powercapability information (S316).

If it is determined that there is not the same parameter type as theparameter type n in the received power capability information in stepS316, a process of step S320 to be described later is performed.

If it is determined that there is the same parameter type as theparameter type n in the received power capability information in stepS316, the power transmission device 100 adds information regarding theparameter type n to a parameter type list defining a parameter type ofpower to be transmitted (S318). Here, for example, the powertransmission device 100 records information of a minimum unit of aparameter of the parameter type n (G shown in FIG. 4) included in thepayload of the power capability information or information of aparameter movable range (H shown in FIG. 4), and the like as theinformation regarding the above-described parameter type n.

If it is determined that there is not the same parameter type as theparameter type n in the received power capability information in stepS316, or if the process of step S318 is performed, the powertransmission device 100 updates the value of n to n=n+1 (S320). Thepower transmission device 100 iterates the process from step S314.

FIG. 14 is an explanatory diagram illustrating a method of determining aparameter type in the arbitration process according to this embodiment.Here, FIG. 14 shows an example of parameter types to be determined bythe process of steps S312 to S320 shown in FIG. 12. In FIG. 14, the casewhere parameter types corresponding to the power transmission device 100are a frequency and a voltage and parameter types corresponding to thepower reception device 200 are a frequency, a voltage, and an azimuthangle is shown.

If the parameter types corresponding to the power transmission device100 and the power reception device 200 are the same as shown in FIG. 14,the power transmission device 100 records information regarding thefrequency and the voltage that are consistent parameter types in aparameter type list by performing the process of steps S312 to S320shown in FIG. 12.

The power transmission device 100 determines a power transmission typeand a parameter type of power to be transmitted to the power receptiondevice 200, for example, by performing the process shown in FIG. 12.Needless to say, the arbitration process according to this embodiment isnot limited to the process shown in FIG. 12.

(2-2) Calibration Process

If the above-described process (arbitration process) of (2-1) isperformed, the power transmission device 100 determines parametercandidates of the power to be transmitted to the power reception device200.

[Specific Example of Calibration Process]

FIG. 15 is a flowchart showing an example of the calibration process inthe power transmission device 100 according to this embodiment.

The power transmission device 100 specifies a parameter having a maximumefficiency value in each power parameter type determined in theabove-described process of (2-1) (S400). More specifically, for example,the power transmission device 100 selects one of the parameter typesrecorded in the parameter type list, and calculates power transmissionefficiencies in all possible parameters in the parameter type bycarrying out an arithmetic operation shown in Equation 1. For example,the power transmission device 100 fixes a parameter corresponding toanother parameter type recorded in the parameter type list when theabove-described power transmission efficiency is calculated. The powertransmission device 100 specifies a parameter having a maximumefficiency value in each parameter type of power by performing theabove-described process for every parameter type recorded in theparameter type list.

FIG. 16 is an explanatory diagram illustrating a process of specifying aparameter having a maximum efficiency value in a parameter type of powerin the calibration process of the power transmission device 100according to this embodiment. Here, FIG. 16 shows an example in whichthree parameter types of a frequency, a voltage, and an azimuth angleare recorded in the parameter type list.

For example, when 300 kHz to 600 kHz can be set in units of 30 kHz for afrequency (an example of a parameter type), the power transmissiondevice 100 carries out measurement and arithmetic operations at 11points in total for the frequency, and fixes the voltage or the azimuthangle, which is another parameter type, to one measurement value duringmeasurement. Through the above, a parameter having the maximumefficiency value at the frequency is specified. The power transmissiondevice 100 specifies parameters having maximum efficiency values by alsoperforming the same process as the process for the above-describedfrequency for the voltage and the azimuth angle, which are the otherparameter types.

Although an example in which a plurality of parameter types are recordedin the parameter type list, for example, as shown in FIG. 16, has beendescribed above, the process in the power transmission device 100according to this embodiment is not limited to the above. For example,even when one parameter type is recorded in the parameter type list, thepower transmission device 100 can specify a parameter having a maximumefficiency value in the parameter type by calculating power transmissionefficiencies for all possible parameters.

The example of the calibration process in the power transmission device100 will be described with reference back to FIG. 15. If the maximumefficiency of each power parameter type is specified in step S400, thepower transmission device 100 sets a standard range of the powertransmission efficiency (which may hereinafter be referred to as a“standard efficiency range”) in each parameter type of the power (S402).

More specifically, as in step S400, the power transmission device 100selects one of the parameter types recorded in the parameter type list,and calculates power transmission efficiencies for all possibleparameters in the selected parameter type. When the above-describedpower transmission efficiencies are calculated, the power transmissiondevice 100 fixes a parameter of another parameter type recorded in theparameter type list to a parameter having a maximum efficiency valuespecified in step S400. The power transmission device 100 sets astandard efficiency range on the basis of efficiency distribution datain which the maximum efficiency value obtained by the above-describedcalculation is on the top. For example, if the top 50% of an efficiencydistribution is designated as a standard and 50% is included in a rangedropped by 10% from a peak efficiency value, the power transmissiondevice 100 sets 80% to 70% as a standard efficiency range.

FIG. 17 is an explanatory diagram illustrating a process of setting astandard range of the power transmission efficiency in a power parametertype in the calibration process of the power transmission device 100according to this embodiment. Here, FIG. 17 shows an example in whichthree parameter types of a frequency, a voltage, and an azimuth angleare recorded in the parameter type list as in FIG. 16.

The power transmission device 100 sets the standard range of the powertransmission efficiency, for example, by performing the process of stepsS400 and S402. In the process of steps S400 and S402, the powertransmission device 100 calculates the power transmission efficiency bycarrying out an arithmetic operation of the above-described Equation 1on the basis of the parameter type list created in the above-describedprocess of (2-1). Here, for example, the power to be transmitted in theprocess related to the calculation of the above-described powertransmission efficiency corresponds to the experimental transmission ofpower by the power transmission device 100 on the basis of a parameterof power that does not exceed the power reception capability of thepower reception device 200 indicated by the power capabilityinformation. For example, the power transmission efficiency calculatedin the process related to the calculation of the above-described powertransmission efficiency corresponds to a power transmission efficiency(hereinafter referred to as “third power transmission efficiency”) ineach parameter of power on the basis of power reception amountinformation (hereinafter referred to as “second power reception amountinformation”) indicating a power reception amount for every parameter ofthe power corresponding to the experimentally transmitted power, thepower reception amount information having been transmitted from thepower reception device 200.

Although an example in which a plurality of parameter types are recordedin the parameter type list, for example, as shown in FIG. 17, has beendescribed above, a process of the power transmission device 100according to this embodiment is not limited to the above. For example,if one parameter type is recorded in the parameter type list, the powertransmission device 100 may not perform the process related to thecalculation of the power transmission efficiency in step S402. In theabove-described case, the power transmission device 100 can set thestandard efficiency range on the basis of efficiency distribution datarelated to the power transmission efficiency calculated in step S400.

The example of the calibration process of the power transmission device100 will be described with reference back to FIG. 15. If the standardefficiency range is set in step S402, the power transmission device 100presents power transmission conditions to the user (S404). Here,examples of the above-described power transmission conditions may be apower transmission unit price and the like.

More specifically, for example, the power transmission device 100calculates the power transmission unit price corresponding to the setstandard efficiency range. The power transmission device 100 transmitsinformation indicating the calculated power transmission unit price tothe power reception device 200, so that a power transmission conditionis presented, for example, by causing a display device included in thepower reception device 200 or an external display device to display thepower transmission unit price on a display screen. The powertransmission device 100 may present the power transmission condition tothe display device (for example, the display section to be describedlater) included in the power transmission device 100.

FIG. 18 is an explanatory diagram showing an example of the displayscreen presented to the user in the calibration process of the powertransmission device 100 according to this embodiment. FIG. 18 shows anexample in which the power transmission device 100 reports the setstandard efficiency range to the user and charges a fee for a totalamount of power transmission. That is, an example shown in FIG. 18 is anexample of a display screen (an example of a power reception siderisk-taking type) displayed when payment for a fluctuation of powertransmission loss is made at the side of the power reception device 200.As shown in FIG. 18, for example, the fact that power transmission isstopped if the first power transmission efficiency calculated by theabove-described Equation 7 is less than a lower limit of the standardefficiency range (an example of a predetermined value) is expressed inthe power transmission conditions presented in step S404.

For example, if the standard efficiency range is 70% to 80% when thepower can be transmitted at 100 yen per kW, the power transmissiondevice 100 presents 125 yen (100/0.8) to 148 yen (100/0.7) as the powertransmission condition. If the first power transmission efficiency isless than 0.7, the power transmission device 100 stops the powertransmission in the process (power transmission process) of (3) to bedescribed later.

The display screen to be presented to the user in the calibrationprocess according to this embodiment is not limited to the example shownin FIG. 18 (an example of a power reception side risk-taking type). FIG.19 is an explanatory diagram showing another example of the displayscreen presented to the user in the calibration process of the powertransmission device 100 according to this embodiment.

FIG. 19 shows an example in which the power transmission device 100 setsa unit price per kW (a uniform unit price not depending upon afluctuation in actual power transmission) on the basis of the standardefficiency range, and charges a fee corresponding to the set unit pricefor a total amount of power transmission. That is, an example shown inFIG. 19 is an example of the display screen (an example of a powertransmission side risk-taking type) displayed when payment for afluctuation of power transmission loss is made at the side of the powertransmission device 100. As shown in FIG. 19, for example, the fact thatpower transmission is stopped if the first power transmission efficiencycalculated by the above-described Equation 7 is less than a lower limitof the standard efficiency range (an example of a predetermined value)is manifested in the power transmission conditions presented in stepS404.

For example, if the standard efficiency range is 70% to 80% when thepower can be transmitted at 100 yen per kW, the power transmissiondevice 100 presents 125 yen (100/0.8) as the power transmissioncondition. If the first power transmission efficiency is less than 0.7corresponding to the lower limit of the standard efficiency range, thepower transmission device 100 stops the power transmission in theprocess (power transmission process) of (3) to be described later.Needless to say, a unit price to be set when the power transmissiondevice 100 sets a power transmission side risk-taking type of thedisplay screen is not limited to that set on the basis of an upper limitof the standard efficiency range as shown in FIG. 19.

In step S404, the power transmission device 100 presents the powertransmission conditions, for example, by presenting the display screenas shown in FIG. 18 or 19, to the user. The power transmission device100 can also audibly report the power transmission conditions through asound.

If the power transmission condition is presented in step S404, the powertransmission device 100 determines whether or not the presented powertransmission condition has been approved (S406). For example, if thepower transmission device 100 has received a power transmission startrequest, transmitted from the power reception device 200, for requestingthe transmission of power according to transmitted informationindicating a power transmission unit price, the presented powertransmission condition is determined to have been approved. Here, thepower reception device 200 transmits the power transmission startrequest, for example, by the user of the power reception device 200operating the power reception device 200 and selecting an OK buttonshown in FIG. 18 or 19. The power transmission device 100 starts theprocess (power transmission process) of (3) to be described later afterthe process of step S408 to be described later by receiving the powertransmission start request.

If it is determined that the presented power transmission condition hasnot been approved in step S406, the power transmission device 100iterates the process from step S400. In the above-described case, forexample, the power transmission device 100 may make a notification (forexample, a visual notification and/or an audible notification) to causethe user to move a position of the power reception device 200 or excludea device other than the power reception device 200.

If the presented power transmission condition is determined to have beenapproved in step S406, the power transmission device 100 sets ablacklist in which an excluded parameter unsuitable for powertransmission among parameters of the power is recorded (S408). Morespecifically, for example, if there is a third power transmissionefficiency outside the set standard range among the third powertransmission efficiencies calculated in step S402, the powertransmission device 100 sets a parameter of the power corresponding tothe third power transmission efficiency outside the standard range to anexclusion parameter. The power transmission device 100 records the setexclusion parameter in the blacklist.

In the process (power transmission process) of (3) to be describedlater, the power transmission device 100 generates parameter informationexcluding the exclusion parameter recorded in the blacklist set in stepS408. That is, the power transmission device 100 can more efficientlytransmit power because the power is not transmitted on the basis of aparameter unsuitable for the power transmission. A parameter of powernot recorded in the blacklist, that is, a parameter of power other thanan exclusion parameter, can be a parameter of power to be transmitted tothe power reception device 200. Consequently, the power transmissiondevice 100 can determine parameter candidates of power to be transmittedto the power reception device 200 by performing the process of stepS408.

FIG. 20 is an explanatory diagram showing an example of a parameter ofpower to be recorded in the blacklist in the calibration process of thepower transmission device 100 according to this embodiment. As shown inFIG. 20, if the third power transmission efficiency calculated incorrespondence with each parameter is less than the lower limit of thestandard efficiency range, it is recorded in the blacklist as anexclusion parameter.

The power transmission device 100 determines parameter candidates ofpower to be transmitted to the power reception device 200, for example,by performing the process shown in FIG. 15. Needless to say, thecalibration process according to this embodiment is not limited to theprocess shown in FIG. 15.

In the power transmission system 1000, the power transmission type andthe parameter candidates of power to be transmitted by the powertransmission device 100 to the power reception device 200 are determinedon the basis of the power capability information, for example, byperforming the process (arbitration process) of (2-1) and the process(calibration process) of (2-2) as described above.

Process (Power Transmission Process) of (3)

If the above-described process (power-parameter candidate determinationprocess) of (2) is performed, the power transmission device 100transmits power by setting any one parameter among parameter candidatesas a parameter to be transmitted for every session.

FIG. 21 is an explanatory diagram showing an example of the powertransmission process in the power transmission system 1000 according tothis embodiment. Here, FIG. 21 shows an example of the powertransmission process in one session (power transmission period). In thepower transmission system 1000, the process shown in FIG. 21 isperformed for every session.

In FIG. 21, a communication section (to be described later) and a powertransmission section (to be described later) among configurations of thepower transmission device 100 are shown, and a communication section (tobe described later) and a power reception section (to be describedlater) among configurations of the power reception device 200 are shown.The communication section of the power transmission device 100 and thecommunication section of the power reception device 200 perform acommunication via the encrypted first communication channel, or thepower transmission section of the power transmission device 100 and thepower reception section of the power reception device 200 transmit andreceive power on the basis of a transmission type and a parameterdefined by parameter information. Hereinafter, the process to beperformed by the communication section or the power transmission sectionof the power transmission device 100 will be described as the process tobe performed by the power transmission device 100, and the process to beperformed by the communication section or the power reception section ofthe power reception device 200 will be described as the process to beperformed by the power reception device 200.

The power transmission device 100 transmits the parameter information tothe power reception device 200 (S500). For example, the process (powertransmission process) of (3) in the power transmission device 100, suchas a process of generating the parameter information, will be describedlater.

FIG. 22 is an explanatory diagram showing an example of parameterinformation to be transmitted by the power transmission device 100according to this embodiment. The parameter information is generated forevery session. Parameters (K shown in FIG. 22) to be used for thetransmission of power in the session are included in the parameterinformation. The parameter information according to this embodiment isnot limited to the example shown in FIG. 22.

FIG. 23 is an explanatory diagram showing another example of parameterinformation to be transmitted by the power transmission device 100according to this embodiment. The parameter information shown in FIG. 23is generated for every session and the parameters (K shown in FIG. 23)of which the number corresponds to the number of steps in the sessionare included in the parameter information. The parameter in each step isset at random among parameter candidates. Needless to say, the parameterinformation according to this embodiment is not limited to the examplesshown in FIGS. 22 and 23.

The example of the power transmission process in the power transmissionsystem 1000 will be described with reference back to FIG. 21. The powerreception device 200 receiving the parameter information transmittedfrom the power transmission device 100 in step S500 makes a response inresponse to a receipt of the parameter information (S502).

FIG. 24 is an explanatory diagram showing an example of a packet to betransmitted when the power reception device 200 makes a response inresponse to a receipt of the parameter information according to thisembodiment. Here, FIG. 24 shows an example of an acknowledgement (ACK)packet. Needless to say, the packet to be transmitted when the powerreception device 200, according to this embodiment, makes the responsein response to the receipt of the parameter information is not limitedto the example shown in FIG. 24.

The example of the power transmission process in the power transmissionsystem 1000 will be described with reference back to FIG. 21. The powertransmission device 100 receiving the response transmitted from thepower reception device 200 in step S502 performs the power transmissionusing a parameter included in the transmitted parameter information ifthe response indicates an ACK (S504). For example, the powertransmission device 100 may re-perform the process of step S500 and stopthe power transmission by reporting the error to the user, if theresponse transmitted from the power reception device 200 in step S502 isa negative acknowledgement (NACK).

FIGS. 25 to 27 are explanatory diagrams showing examples in which thepower transmission device 100 according to this embodiment transmitspower on the basis of the parameter information. Here, FIGS. 25 to 27show the examples in which the power transmission device 100, accordingto this embodiment, transmits power on the basis of the parameterinformation shown in FIG. 22. FIG. 25 shows an example in which power istransmitted by a continuous wave, and a frequency (f shown in FIG. 25),a voltage (v shown in FIG. 25), and a power transmission time (t shownin FIG. 25) are set on the basis of the parameter information in eachstep. FIG. 26 shows an example in which power is transmitted in a timedivision type, and a frequency (f shown in FIG. 26), a voltage (v shownin FIG. 26), and a power transmission slot offset are set on the basisof the parameter information in each step. FIG. 27 is an example inwhich an azimuth angle is controlled on the basis of parameterinformation, and the azimuth angle is set on the basis of the parameterinformation.

Power to be transmitted by the power transmission device 100 accordingto this embodiment on the basis of the parameter information is notlimited to the examples shown in FIGS. 25 and 27. For example, if thepower transmission device 100 transmits the power in the time divisiontype, a minimum slot shown in FIG. 26 may be variable and/or the powermay be continuously transmitted in a period of a plurality of minimumslots.

For example, if the parameter information shown in FIG. 23 istransmitted in step S500, the power transmission device 100 can alsotransmit power on the basis of parameter information in which aparameter of power to be transmitted for every session is set at random.

FIGS. 28 to 30 are explanatory diagrams showing other examples in whichthe power transmission device 100 transmits power on the basis ofparameter information. Here, FIGS. 28 to 30 show examples of power to betransmitted by the power transmission device 100 on the basis of theparameter information shown in FIG. 23. FIG. 28 shows an example inwhich power is continuously transmitted as in FIG. 25, and a frequency(f shown in FIG. 28), a voltage (v shown in FIG. 28), and a powertransmission time (t shown in FIG. 28) are variable on the basis of theparameter information in each step. A minimum slot shown in FIG. 29 maybe variable, and/or power may be continuously transmitted in a period ofa plurality of minimum slots. FIG. 29 shows an example in which power istransmitted in a time division type as in FIG. 26, and a frequency (fshown in FIG. 29), a voltage (v shown in FIG. 29), and a powertransmission slot offset are variable on the basis of the parameterinformation in each step. FIG. 30 shows an example in which an azimuthangle is controlled on the basis of the parameter information as in FIG.27, and the azimuth angle is variable on the basis of the parameterinformation.

The example of the power transmission process in the power transmissionsystem 1000 will be described with reference back to FIG. 21. The powerreception device 200 receiving the power transmitted in step S504 on thebasis of the parameter information received in step S500 transmits apower reception report (S506).

FIG. 31 is an explanatory diagram showing an example of the powerreception report transmitted by the power reception device 200 accordingto this embodiment. First power reception amount information (L shown inFIG. 31; each power reception amount is indicated, for example, inwatts) indicating a power reception amount for every power parameterindicated by the parameter information is included in the powerreception report. Needless to say, the power reception report accordingto this embodiment is not limited to the example shown in FIG. 31.

The example of the power transmission process in the power transmissionsystem 1000 will be described with reference back to FIG. 21. The powertransmission device 100 receiving the power reception report transmittedfrom the power reception device 200 in step S506 makes a response inresponse to a receipt of the power reception report (S508).

FIG. 32 is an explanatory diagram showing an example of a packet to betransmitted when the power transmission device 100 makes a response inresponse to a receipt of the power reception report according to thisembodiment. Here, FIG. 32 is an example of an ACK packet. Needless tosay, the packet to be transmitted when the power transmission device 100makes the response in response to the receipt of the power receptionreport according to this embodiment is not limited to the example shownin FIG. 32.

In the power transmission system 1000, for example, the process shown inFIG. 21 in each session (power transmission period) is performed betweenthe power transmission device 100 and the power reception device 200.Next, the process (power transmission process) of (3) in the powertransmission device 100 will be more specifically described.

[Specific Example of Power Transmission Process in Power TransmissionDevice 100]

FIG. 33 is a flowchart showing an example of the power transmissionprocess in the power transmission device 100 according to thisembodiment. Here, a process of steps S600 to S612 shown in FIG. 33corresponds to the power transmission process in one session (powertransmission period).

The power transmission device 100 sets parameters (S600: parametersetting process). Here, for example, the power transmission device 100sets the parameters by selecting one parameter at random among parametercandidates set in the above-described process (power-parameter candidatedetermination process) of (2) when the parameter information shown inFIG. 22 is transmitted in step S602 to be described later. A method ofsetting parameters in the power transmission device 100 according tothis embodiment is not limited to the above.

<Other Example of Parameter Setting Process in Power Transmission Device100>

FIG. 34 is a flowchart showing an example of the parameter settingprocess in the power transmission device 100 according to thisembodiment. Here, FIG. 34 shows an example of the parameter settingmethod when the power transmission device 100 transmits the parameterinformation shown in FIG. 23 in step S602 of FIG. 33 to be describedlater.

The power transmission device 100 sets the value of n to n=0 (zero)(S700). Here, for example, the value of n indicates a number indicatinga parameter type recorded in a parameter type list.

If the process of step S700 is performed, the power transmission device100 determines whether or not the value of n is less than the number ofparameter types recorded in the parameter type list (S702).

If the value of n is determined not to be less than the number ofparameter types recorded in the parameter type list in step S702, thepower transmission device 100 ends the parameter setting process.

If the value of n is determined to be less than the number of parametertypes recorded in the parameter type list in step S702, the powertransmission device 100 inputs a random number to a PN code, andcalculates a random sequence from 0 to M−1 (the total number of stepsper session) in each step (S704).

If the process of step S704 is performed, the power transmission device100 derives a parameter corresponding to a parameter type n (S706). Thepower transmission device 100 performs the process of step S706, forexample, by use of a conversion table corresponding to the parametertype n.

FIG. 35 is an explanatory diagram showing an example of a conversiontable used by the power transmission device 100 to derive a parametercorresponding to a certain parameter type according to this embodiment.Here, FIG. 35 shows an example of the conversion table when theparameter type is a frequency. M shown in FIG. 35 indicates an exclusionparameter or a parameter (which is a parameter unused in powertransmission; hereinafter, the parameter may be referred to as a“non-use parameter”) newly recorded in the blacklist in step S610 ofFIG. 33 to be described later. The power transmission device 100 updatesthe conversion table, for example, associated with the blacklist set instep S408 of FIG. 15. The conversion table according to this embodimentmay function as the backlist itself. Needless to say, the conversiontable according to this embodiment is not limited to FIG. 33.

The example of the parameter setting process in the power transmissiondevice 100 will be described with reference back to FIG. 34. If theprocess of step S706 is performed, the power transmission device 100updates the value of n to n=n+1 (S708). The power transmission device100 iterates the process from step S702.

The power transmission device 100 can set a random parameter for everystep for each parameter type recorded in a parameter type list, forexample, by performing the process shown in FIG. 34.

When the parameter information shown in FIG. 23 is transmitted in stepS602 of FIG. 33 to be described later, the parameter setting process inthe power transmission device 100 according to this embodiment is notlimited to the process shown in FIG. 34. FIG. 36 is a flowchart showinganother example of the parameter setting process in the powertransmission device 100 according to this embodiment. Here, like FIG.34, FIG. 36 shows an example of the parameter setting method when thepower transmission device 100 transmits the parameter information shownin FIG. 23 in step S602 of FIG. 33 to be described later.

The power transmission device 100 sets the value of n to n=0 (zero) asin step S700 of FIG. 34 (S800)

If the process of step S800 is performed, the power transmission device100 determines whether or not the value of n is less than the number ofparameter types recorded in the parameter type list as in step S702 ofFIG. 34 (S802).

If the value of n is determined not to be less than the number ofparameter types recorded in the parameter type list in step S802, thepower transmission device 100 ends the parameter setting process.

If the value of n is determined to be less than the number of parametertypes recorded in the parameter type list in step S802, the powertransmission device 100 inputs a random number to a PN code, andcalculates a random sequence from 0 to M−1 (the total number of stepsper session) in each step as in step S704 of FIG. 34 (S804).

If the process of step S804 is performed, the power transmission device100 derives a parameter corresponding to a parameter type n (S806). Thepower transmission device 100 performs the process of step S806, forexample, using a conversion table corresponding to the parameter type n.

FIG. 37 is an explanatory diagram showing another example of theconversion table used by the power transmission device 100 to derive aparameter corresponding to a certain parameter type according to thisembodiment. Here, like FIG. 35, FIG. 37 shows an example of theconversion table when the parameter type is a frequency. N shown in FIG.37 indicates an exclusion parameter, and O shown in FIG. 37 indicates aparameter (non-use parameter) newly recorded in the blacklist in stepS610 of FIG. 33 to be described later.

A blacklist shown in FIG. 37 is a flag indicating a parameter recordedin the blacklist. In FIG. 37, the flag of “1” indicates that there is aparameter recorded in each blacklist. A blacklist candidate shown inFIG. 37 indicates a parameter that is likely to be registered in theblacklist.

More specifically, the power transmission device 100 sets a targetparameter to a non-use candidate parameter serving as a non-useparameter candidate, for example, in step S610 of FIG. 33 to bedescribed later, and updates a value of a blacklist candidatecorresponding to the non-use candidate parameter every time the non-usecandidate parameter is set. The power transmission device 100 sets aparameter of power, which is set to a non-use candidate parameter apredetermined number of times (for example, five times in an exampleshown in FIG. 37) in a fixed period, to a non-use parameter. The powertransmission device 100 updates a blacklist value corresponding to aparameter set to the non-use parameter to “1” (blacklist).

For example, the power transmission device 100 may periodically oraperiodically release the setting of the non-use parameter or thenon-use candidate parameter set in FIG. 37. Here, a parameter of powercorresponding to a non-use parameter or a non-use candidate parameteraccording to this embodiment does not correspond to the exclusionparameter. That is, even when the above-described parameter isregistered in the blacklist as the non-use parameter, it is possible tonormally re-transmit/re-receive power if an environment according topower transmission in the power transmission system 1000 is varied.Consequently, the power transmission device 100 sets as many powerparameters as possible to be used for power transmission by periodicallyor aperiodically releasing the setting of the non-use parameter or thenon-use candidate parameter as described above, thereby preventingunauthorized power reception by a device other than the power receptiondevice 200.

Needless to say, the conversion table according to this embodiment isnot limited to FIG. 37.

Another example of the parameter setting process in the powertransmission device 100 will be described with reference back to FIG.36. If the process of step S806 is performed, the power transmissiondevice 100 determines whether or not the parameter derived in step S806is registered in the blacklist (S808). The power transmission device 100determines whether the parameter set for each step is registered in theblacklist, for example, by referring to the conversion table shown inFIG. 37.

If it is determined that there is a parameter registered in theblacklist in step S808, the parameter sequence calculated in step S804is updated by the newly generated random number value (S810), and theprocess from step S806 is re-performed.

If it is determined that there is not the parameter registered in theblacklist in step S808, the power transmission device 100 updates thevalue of n to n=n+1 as in step S708 of FIG. 34 (S812). The powertransmission device 100 iterates the process from step S802.

The power transmission device 100 can set a random parameter for everystep in each parameter type recorded in the parameter type list, as inthe case where the process shown in FIG. 34 is performed, for example,by performing the process shown in FIG. 36.

When the parameter information shown in FIG. 23 is transmitted in stepS602 of FIG. 33 to be described later, the power transmission device 100sets a parameter, for example, by performing the process shown in FIG.34 or 36. Needless to say, the parameter setting process in the powertransmission device 100 according to this embodiment is not limited tothe processes shown in FIGS. 34 and 36 when the parameter informationshown in FIG. 23 is transmitted in step S602 of FIG. 33 to be describedlater.

The example of the power transmission process in the power transmissiondevice 100 will be described with reference back to FIG. 33. If aparameter is set in step S600, the power transmission device 100generates parameter information including a parameter set for everystep, and transmits the parameter information to the power receptiondevice 200 (S602). Here, the process of step S602 corresponds to theprocess of step S500 in FIG. 21.

Upon receipt of a response (for example, a response packet indicatingthe ACK shown in FIG. 24) from the power reception device 200 to theparameter information transmitted in step S602, the power transmissiondevice 100 transmits power on the basis of the parameter information,that is, on the basis of the set parameter (S604). Here, the process ofstep S604 corresponds to the process of step S504 in FIG. 21.

If the power is transmitted in step S604, the power transmission device100 determines whether or not a power reception report has been received(S606). If the power reception report is determined not to have beenreceived in step S606, the power transmission device 100 does notperform the process until the power reception report is received. If thepower reception report is not received a predetermined time after thepower is transmitted, the power transmission device 100 may end thepower transmission (timeout), for example, without transmitting power ina subsequent session.

If the power reception report is determined to have been received instep S606, the power transmission device 100 calculates a second powertransmission efficiency (power transmission efficiency of everysession), and determines whether or not the second power transmissionefficiency is less than the lower limit of the standard efficiency range(S608).

If the second power transmission efficiency is determined not to be lessthan the lower limit of the standard efficiency range in step S608, thepower transmission device 100 performs a process of step S612 to bedescribed later.

If the second power transmission efficiency is determined to be lessthan the lower limit of the standard efficiency range in step S608, thepower transmission device 100 performs a blacklist update process(S610).

More specifically, if the second power transmission efficiency isdetermined to be less than the lower limit of the standard efficiencyrange, the power transmission device 100 sets a non-use parameter, forexample, on the basis of a parameter of the power indicated by parameterinformation corresponding to a session for which the second powertransmission efficiency is calculated. The power transmission device 100performs the process of step S610, for example, by recording a parameterset to the non-use parameter in the blacklist.

Here, for example, the power transmission device 100 immediately sets aparameter of power indicated by the above-described parameterinformation to the non-use parameter, but the process in the powertransmission device 100 is not limited to the above. For example, thepower transmission device 100 can set each parameter of power indicatedby the above-described parameter information to the non-use candidateparameter, and, for example, can set a parameter of power, which is setto the non-use candidate parameter a predetermined number of times in afixed period, to the non-use parameter. For example, the powertransmission device 100 may periodically or aperiodically release thesetting of the set non-use parameter or non-use candidate parameter.When power is transmitted on the basis of parameter information in whichthe parameter shown in FIG. 23 is set at random in step S604, the powertransmission device 100 may update, for example, the conversion tableshown in FIG. 37, as the process in step S610.

If the second power transmission efficiency is determined not to be lessthan the lower limit of the standard efficiency range in step S608, orif the process of step S610 is performed, the power transmission device100 calculates the first power transmission efficiency (the powertransmission efficiency in a power transmission period in which powerhas been transmitted), and determines whether or not the first powertransmission efficiency is less than the lower limit of the standardefficiency range (S612).

If the first power transmission efficiency is determined to be less thanthe lower limit of the standard efficiency range in step S612, the powertransmission device 100 ends the power transmission without transmittingthe power in a subsequent session (S616). The power transmission isautomatically stopped if the power transmitted by the power transmissiondevice 100 is not received normally in the power reception device 200when the process of step S616 is performed and the transmitted power isreceived by a non-target device of the power transmission. Therefore,the power transmission device 100 can prevent the power from beingreceived by the non-target device of the power transmission by stoppingthe power transmission if the first power transmission efficiency isless than the predetermined value.

If the first power transmission efficiency is determined not to be lessthan the lower limit of the standard efficiency range in step S612, thepower transmission device 100 determines whether or not to end the powertransmission (S614). Here, for example, when a power transmission stoprequest for requesting the stop of transmission of power, transmittedfrom the power reception device 200, is received, or when the powertransmission stop request is transferred on the basis of the user'soperation from an operating section (to be described later) included inthe power transmission device 100, the power transmission device 100determines to end the power transmission. For example, if a total amountof power transmission exceeds a predetermined value (for example, avalue set by the user before power transmission), the power transmissiondevice 100 may determine to end the power transmission.

If the power transmission is determined not to be ended in step S614,the power transmission device 100 iterates the process from step S600.

If the power transmission is determined to be ended in step S614, thepower transmission device 100 ends the power transmission (S616).

For example, the process shown in FIG. 33 is performed, so that thepower transmission device 100 can transmit power by randomly setting aparameter of power to be transmitted for every session. Needless to say,the process (power transmission process) of (3) in the powertransmission device 100 according to this embodiment is not limited tothe process shown in FIG. 33.

In the power transmission system 1000, for example, the process(communication channel establishment process) of (1) to the process(power transmission process) of (3) are performed, so that power istransmitted between the power transmission device 100 and the powerreception device 200. Here, in the power transmission system 1000, thetransmission/reception of the parameter information in which a parameterof power is set is performed between the power transmission device 100and the power reception device 200 by the encrypted first communicationchannel formed by the above-described process (communication channelestablishment process) of (1). The power transmission device 100transmits the power by use of a parameter indicated by the transmittedparameter information, and the power reception device 200 receives thepower by use of the parameter indicated by the received parameterinformation. Here, the power transmission device 100 acquires powercapability information from the power reception device 200 before thepower transmission is performed, and sets parameter candidates of thepower that does not exceed a power reception capability indicated by theacquired power capability information. In the above-described process(power-parameter candidate determination process) of (2), the powertransmission device 100 sets a parameter at which a power transmissionefficiency equal to or greater than a certain fixed level can beacquired in an actual environment where the power is transmitted fromamong parameters of the power that does not exceed the power receptioncapability indicated by the power capability information acquired fromthe power reception device 200, as a parameter candidate of power. Thepower transmission device 100 transmits the power by use of any oneparameter among the set parameter candidates of the power. Therefore,the process (communication channel establishment process) of (1) to theprocess (power transmission process) of (3) are performed, so that thepower transmission device 100 can transmit the power to the powerreception device 200 by use of a parameter corresponding to anenvironment where the power is transmitted, and the power transmissionsystem capable of reducing a power transmission loss is implemented.

(Power Transmission System According to One Embodiment)

Next, a configuration example of the power transmission device 100 andthe power reception device 200 constituting the power transmissionsystem 1000 capable of implementing the process related to the powertransmission approach according to this embodiment described above willbe described. FIG. 38 is a block diagram showing an example of eachconfiguration of the power transmission device 100 and the powerreception device 200 constituting the power transmission system 1000according to this embodiment.

[Power Transmission Device 100]

The power transmission device 100 includes a storage section 102, acommunication section (first communication section) 104, a powertransmission section 106, and a control section 108.

The power transmission device 100 may include, for example, a read onlymemory (ROM) (not shown) or a random access memory (RAM) (not shown), anoperating section (not shown) capable of being operated by the user, adisplay section (not shown) that displays various screens on a displayscreen, and the like. The power transmission device 100 establishes aconnection between the above-described components by a bus, for example,as a transmission path for data.

The ROM (not shown) stores programs to be used by the control section108 and control data such as arithmetic parameters. The RAM (not shown)temporarily stores programs and the like to be executed by the controlsection 108.

An example of the operating section (not shown) may be a button, adirection key, or a combination thereof. An example of the displaysection (not shown) may be a liquid crystal display (LCD), an organicelectroluminescence (EL) display (which is also called an organic lightemitting diode (OLED) display), or the like. The power transmissiondevice 100 may be connected to an operation input device (for example, akeyboard, a mouse, or the like) or a display device as an externaldevice of the power transmission device 100.

[Hardware Configuration Example of Power Transmission Device 100]

FIG. 39 is an explanatory diagram showing the hardware configurationexample of the power transmission device 100 according to thisembodiment. Referring to FIG. 39, the power transmission device 100includes, for example, an antenna circuit 150, a carrier transmissioncircuit 152, a micro processing unit (MPU) 154, a ROM 156, a RAM 158, arecording medium 160, an input/output interface 162, an operation inputdevice 164, a display device 166, and a communication interface 168. Thepower transmission device 100 establishes a connection between theabove-described components by a bus 170, for example, as a transmissionpath for data.

The antenna circuit 150 and the carrier transmission circuit 152function as the power transmission section 106 of the power transmissiondevice 100. Consequently, the antenna circuit 150 and the carriertransmission circuit 152 can be configured, for example, to haveconfigurations corresponding to FIGS. 5 to 9, so as to implement theabove-described first to fourth power transmission types. For example,the antenna circuit 150 related to the first transmission type includesa resonant circuit including a coil having a predetermined inductanceand a capacitor having a predetermined capacitance as atransmitting/receiving antenna. The carrier transmission circuit 152related to the first transmission type is configured, for example, toinclude an AC power supply, an amplification circuit that amplifies anoutput of the AC power supply, and the like.

The MPU 154 is a processing means and is constituted, for example, by anMPU, a power measurement circuit, an integrated circuit into which aplurality of circuits are integrated to implement a control function, orthe like, and functions as the control section 108 that controls theentire power transmission device 100. In the power transmission device100, the MPU 154 can function as a parameter information generationsection 120, a communication control section 122, a power transmissioncontrol section 124, and a power transmission efficiency calculationsection 126.

The ROM 156 stores programs to be used by the MPU 154 and control datasuch as arithmetic parameters, and the RAM 158 temporarily storesprograms and the like to be executed by the MPU 154.

The recording medium 160 is a storage means included in the powertransmission device 100, and functions as the storage section 102. Therecording medium 160 stores, for example, power capability information,a blacklist, a conversion table, an application, and the like. Examplesof the storage section 160 may be a magnetic recording medium such as ahard disk, a nonvolatile memory such as an electrically erasableprogrammable read-only memory (EEPROM), flash memory, magnetoresistiverandom access memory (MRAM), ferroelectric random access memory (FeRAM),or phase-change random access memory (PRAM), and the like.

The input/output interface 162 is connected to, for example, theoperation input device 164 or the display device 166. The operationinput device 164 functions as an operating section (not shown), and thedisplay device 166 functions as a display section (not shown). Here,examples of the input/output interface 162 may be a universal serial bus(USB) terminal, a digital visual interface (DVI) terminal, ahigh-definition multimedia interface (HDMI) terminal, various processingcircuits, and the like. The operation input device 164 is provided, forexample, on the power transmission device 100, and is connected to theinput/output interface 162 inside the power transmission device 100. Anexample of the operation input device 164 may be a button, a directionkey, a rotary selector such as a jog dial, or a combination thereof. Thedisplay device 166 is provided, for example, on the power transmissiondevice 100, and is connected to the input/output interface 162 insidethe power transmission device 100. An example of the display device 166may be an LCD or an organic EL display. Needless to say, theinput/output interface 162 can be connected to an operation input device(for example, a keyboard, a mouse, or the like) or a display device (forexample, an external display or the like) as an external device of thepower transmission device 100. Needless to say, the display device 166may be a device on which a displaying operation and the user's operationare possible such as a touch screen.

The communication interface 168 is a communication means included in thepower transmission device 100, and functions as the communicationsection 104 for performing wireless/wired communication with an externaldevice such as the power reception device 200. Here, examples of thecommunication interface 168 may be a communication antenna and a radiofrequency (RF) circuit, an IEEE 802.15.1 port and atransmission/reception circuit, an IEEE 802.11b port and atransmission/reception circuit, a LAN terminal and atransmission/reception circuit (wired communication), and the like.

The power transmission device 100 performs the process related to thepower transmission approach according to this embodiment describedabove, for example, by the hardware configuration as shown in FIG. 39.The hardware configuration of the power transmission device 100according to this embodiment is not limited to the configuration shownin FIG. 39. For example, the power transmission device 100 may include aplurality of antenna circuits 150 and a plurality of carriertransmission circuits 152 related to different transmission types. Thepower transmission device 100 may include, for example, a digital signalprocessor (DSP) and an audio output display including an amplifier or aspeaker. In the above-described case, the power transmission device 100can audibly report an error, for example, by outputting an error soundfrom the above-described audio output device in step S304 of FIG. 12.The power transmission device 100 may not include, for example, theoperating device 164 or the display device 166 shown in FIG. 39.

The configuration of the power transmission device 100 will be describedwith reference back to FIG. 38. The storage section 102 is a storagemeans included in the power transmission device 100. Here, examples ofthe storage section 102 may be a magnetic recording medium such as ahard disk, and a nonvolatile memory such as a flash memory.

The storage section 102 stores, for example, power capabilityinformation, a blacklist, a conversion table, an application, and thelike. Here, an example in which power capability information 130 isstored in the storage section 102 is shown in FIG. 38.

The communication section 104 is a communication means included in thepower transmission device 100, and functions to perform wireless/wiredcommunication with an external device such as the power reception device200. Here, examples of the communication interface 168 may be acommunication antenna and an RF circuit, an IEEE 802.15.1 port and atransmission/reception circuit, a LAN terminal and atransmission/reception circuit, and the like, but the configuration ofthe communication section 104 is not limited to the above. Thecommunication of the communication section 104 is controlled, forexample, by the control section 108 (more precisely, the communicationcontrol section 122 to be described later).

The power transmission section 106 is a power transmission meansincluded in the power transmission device 100, and functions towirelessly transmit power to the power reception device 200. Here, thepower transmission section 106 transmits the power to the powerreception device 200 by use of electromagnetic induction (the firsttransmission type), electric waves (the second transmission type), orelectric- or magnetic-field resonance (the third or fourth transmissiontype). The power transmission of the power transmission section 106 iscontrolled, for example, by the control section 108 (more precisely, thepower transmission control section 124 to be described later).

The control section 108 is constituted, for example, by an MPU or thelike, and functions to control the entire power transmission device 100.The control section 108 includes a parameter information generationsection 120, a communication control section 122, the power transmissioncontrol section 124, and a power transmission efficiency calculationsection 126, and functions to initiatively perform a process related tothe power transmission approach according to this embodiment.

The parameter information generation section 120 functions toinitiatively perform parts of the above-described process(power-parameter candidate determination process) of (2) and theabove-described process (power transmission process) of (3). Morespecifically, for example, the parameter information generation section120 generates parameter information including any one parameter amongset power parameter candidates for every session (power transmissionperiod).

Here, the parameter information generation section 120 sets the standardefficiency range, for example, on the basis of the third powertransmission efficiency (power transmission efficiency in each powerparameter corresponding to experimentally transmitted power) calculatedby the power transmission efficiency calculation section 126, in theabove-described process (power-parameter candidate determinationprocess) of (2), and sets a parameter of power corresponding to thethird power transmission efficiency to an exclusion parameter if thethird power transmission efficiency is outside the standard range. Ifthe second power transmission efficiency (power transmission efficiencyfor every session) calculated by the power transmission efficiencycalculation section 126 is less than a predetermined value (for example,the lower limit of the standard efficiency range) in the above-describedprocess (power transmission process) of (3), the parameter informationgeneration section 120 sets a non-use parameter candidate or a non-useparameter on the basis of a parameter of power indicated by theparameter information corresponding to a session of the second powertransmission efficiency. In the above-described process (powertransmission process) of (3), the parameter information generationsection 120 generates parameter information excluding an exclusionparameter or a non-use parameter. The parameter information generationsection 120 may periodically or aperiodically release the setting of thenon-use parameter or the non-use candidate parameter.

For example, if the communication section 104 has received the powertransmission start request transmitted from the power reception device200, the parameter information generation section 120 generates theparameter information.

The communication control section 122 controls communication of thecommunication section 104, and functions to initiatively perform part ofthe above-described process (communication channel establishmentprocess) of (1) and the above-described process (power transmissionprocess) of (3). More specifically, in the above-described process(communication channel establishment process) of (1), the communicationcontrol section 122 causes the communication section 104 to transmit thepower capability information transmission request before the powertransmission of the power transmission section 106 is started, forexample, after the encrypted first communication channel is formed, andcauses the power reception device 200 to transmit the power capabilityinformation. The communication control section 122 transfers the powercapability information received by the communication section 104 to theparameter information generation section 120. The power capabilityinformation is transferred, so that the parameter information generationsection 120 can generate the parameter information including a parameterof power that does not exceed the power reception capability of thepower reception device 200 indicated by the power capabilityinformation.

In the above-described process (power transmission process) of (3), forexample, the communication control section 122 causes informationindicating a power transmission unit price calculated by the powertransmission control section 124 to be transmitted to the powerreception device 200. Upon receipt of the power transmission startrequest transmitted from the power reception device 200 according to theinformation indicating the above-described power transmission unitprice, the communication section 104 transfers a power transmissionstart request to the parameter information generation section 120.

In the above-described process (power transmission process) of (3), thecommunication control section 122 sequentially transmits, for example,the parameter information generated by the parameter informationgeneration section 120, to the communication section 104 for everysession.

The power transmission control section 124 controls a power transmissionof the power transmission section 106, and functions to initiativelyperform part of the above-described process (power-parameter candidatedetermination process) of (2) and the above-described process (powertransmission process) of (3). More specifically, in the above-describedprocess (power-parameter candidate determination process) (2), the powertransmission control section 124 transmits power to the powertransmission section 106 on the basis of a parameter of power that doesnot exceed the power reception capability of the power reception device200 indicated by the power capability information. The powertransmission control section 124 calculates a power transmission unitprice corresponding to the standard efficiency range set by theparameter information generation section 120, and transfers thecalculated power transmission unit price to the communication controlsection 122.

In the above-described process (power transmission process) of (3), forexample, the power transmission control section 124 causes the powertransmission section 106 to transmit the power on the basis of aparameter of power indicated by the parameter information. For example,if the first power transmission efficiency calculated by the powertransmission efficiency calculation section 126 is less than apredetermined value (for example, the lower limit of the standardefficiency range), the power transmission control section 124 causes thepower transmission section 106 not to transmit the power. In theabove-described case, the power transmission from the power transmissiondevice 100 to the power reception device 200 is automatically stopped.

The power transmission efficiency calculation section 126 functions toinitiatively perform part of the above-described process(power-parameter candidate determination process) of (2) and theabove-described process (power transmission process) of (3). Morespecifically, the power transmission efficiency calculation section 126functions to calculate the first power transmission efficiency, thesecond power transmission efficiency, and the third power transmissionefficiency.

The control section 108 can initiatively perform the process (theprocess of (1) to the process of (3)) related to the power transmissionapproach related to the embodiment described above, for example, byincluding the parameter information generation section 120, thecommunication control section 122, the power transmission controlsection 124, and the power transmission efficiency calculation section126. The configuration of the control section 108 according to thisembodiment is not limited to the above. For example, the control section108 of the power transmission device 100 according to this embodimentmay include a part having a plurality of functions among the parameterinformation generation section 120, the communication control section122, the power transmission control section 124, and the powertransmission efficiency calculation section 126. In the control section108, each of the parameter information generation section 120, thecommunication control section 122, the power transmission controlsection 124, and the power transmission efficiency calculation section126 may have a configuration sub-divided into a plurality of parts foreach function.

The power transmission device 100 can perform the process (communicationchannel establishment process) of (1) to the process (power transmissionprocess) of (3) related to the power transmission approach related tothe embodiment described above, for example, by the configuration shownin FIG. 38. Therefore, the power transmission device 100 can reducepower transmission loss, for example, by the configuration shown in FIG.38.

The configuration of the power transmission device 100 according to thisembodiment is not limited to the configuration shown in FIG. 38. Forexample, the power transmission device 100 may have a secondcommunication section (not shown) capable of communicating with anexternal device such as the power reception device 200 by the secondcommunication channel. Here, examples of the second communicationsection (not shown) may be a resonant circuit including a coil having apredetermined inductance and a capacitor having a predeterminedcapacitance as a transmission/reception antenna, an AC power supply, anamplification circuit that amplifies an output of the AC power supply,and the like (an example of a configuration for performing acommunication by a communication channel formed by NFC). Theconfiguration of the second communication section (not shown) is notlimited to the above, and the second communication section (not shown)may be constituted, for example, by an infrared port and atransmission/reception circuit (an example of a configuration forperforming a communication by a communication channel formed by aninfrared communication).

In the above-described case, the communication control section 122 ofthe power transmission device 100 can improve the convenience of theuser in the above-described process (communication channel establishmentprocess) of (1) by causing connection information to be transmitted tothe power reception device 200 via the second communication channel. Inthe above-described case, the communication control section 122 of thepower transmission device 100 transmits the power capability informationtransmission request to the second communication section, and transfersthe power capability information received by the second communicationsection (not shown) to the parameter information generation section 120.The power capability information is transferred, so that the parameterinformation generation section 120 can generate parameter informationincluding a parameter of power that does not exceed the power receptioncapability of the power reception device 200 indicated by the powercapability information.

If the second communication channel is formed by NFC, the secondcommunication section (not shown) can function as the power transmissionsection 106.

[Power Reception Device 200]

Next, an example of a configuration of the power reception device 200according to this embodiment will be described. The power receptiondevice 200 includes a storage section 202, a communication section 204,a power reception section 206, and a control section 208.

The power reception device 200 may include, for example, a ROM (notshown) storing programs to be used by the control section 208 andcontrol data such as arithmetic parameters or a RAM (not shown)temporarily storing programs and the like to be executed by the controlsection 208, an operating section (not shown) capable of being operatedby the user of the power reception device 200, a display section (notshown) that displays various screens on a display screen, and the like.The power reception device 200 establishes a connection between theabove-described components by a bus, for example, as a transmission pathfor data.

Here, an example of the operating section (not shown) may be anoperation input device such as a keyboard or a mouse, a button, adirection key, or a combination thereof. An example of the displaysection (not shown) may be an LCD, an EL display, or the like. The powerreception device 200 may be connected to an operation input device (forexample, a keyboard, a mouse, or the like) or a display device as anexternal device of the power reception device 200.

[Hardware Configuration Example of Power Reception Device 200]

FIG. 40 is an explanatory diagram showing the hardware configurationexample of the power reception device 200. Referring to FIG. 40, thepower reception device 200 includes, for example, an antenna circuit250, an MPU 252, a ROM 254, a RAM 256, a recording medium 258, aninput/output interface 260, an operation input device 262, a displaydevice 264, a communication interface 266, and an internal power supply268. The power reception device 200 establishes a connection between theabove-described components by a bus 270, for example, as a transmissionpath for data.

The antenna circuit 250 functions as the power reception section 206 inthe power reception device 200. The antenna circuit 250 is configured,for example, in correspondence with FIGS. 5 to 9, so as to implement theabove-described first to fourth power transmission types. The powerreception device 200 may include a plurality of antenna circuits 250related to different transmission types.

The MPU 252 is a processing means and is constituted, for example, by anMPU, a power measurement circuit, an integrated circuit into which aplurality of circuits are integrated to implement a control function, orthe like, and functions as the control section 208 that controls theentire power reception device 200. The ROM 254 stores programs to beused by the MPU 252 and control data such as arithmetic parameters, andthe RAM 256 temporarily stores programs and the like to be executed bythe MPU 252.

The recording medium 258 is a storage means included in the powerreception device 200, and stores power capability information, anapplication, and the like. Here, examples of the recording medium 258may be a magnetic recording medium such as a hard disk, a nonvolatilememory such as EEPROM, flash memory, MRAM, FeRAM, and PRAM, and thelike.

The input/output interface 260 is connected to, for example, theoperation input device 262 or the display device 264. The operationinput device 262 functions as an operating section (not shown), and thedisplay device 264 functions as a display section (not shown). Here,examples of the input/output interface 260 may be a USB terminal, a DVIterminal, an HDMI terminal, various processing circuits, and the like.The operation input device 262 is provided, for example, on the powerreception device 200, and is connected to the input/output interface 260inside the power reception device 200. An example of the operation inputdevice 262 may be a button, a direction key, a rotary selector such as ajog dial, or a combination thereof. The display device 264 is provided,for example, on the power reception device 200, and is connected to theinput/output interface 260 inside the power reception device 200. Anexample of the display device 264 may be an LCD or an organic ELdisplay. Needless to say, the input/output interface 260 can beconnected to an operation input device (for example, a keyboard, amouse, or the like) or a display device (for example, an externaldisplay or the like) as an external device of the power reception device200. Needless to say, the display device 264 may be a device on which adisplaying operation and the user's operation are possible such as atouch screen.

The communication interface 266 is a communication means included in thepower reception device 200, and functions as the communication section204 for performing wireless/wired communication with an external devicesuch as the power transmission device 100. Here, examples of thecommunication interface 266 may be a communication antenna and an RFcircuit (wireless communication), an IEEE 802.15.1 port and atransmission/reception circuit (wireless communication), an IEEE 802.11bport and a transmission/reception circuit (wireless communication), aLAN terminal and a transmission/reception circuit (wired communication),and the like.

The internal power supply 268 is a power supply that can charge thereceived power and supply a driving voltage to drive each part of thepower reception device 200 and is included in the power reception device200. Here, an example of the internal power supply 268 may be asecondary battery such as a lithium-ion rechargeable battery.

The power reception device 200 can receive power transmitted from thepower transmission device 100 by the hardware configuration as shown inFIG. 40. Therefore, the power reception device 200 can configure thepower transmission system 1000 capable of wirelessly transmitting powerto the power reception device 200 while preventing devices other thanthe power reception device 200 from performing unauthorized powerreception by the hardware configuration as shown in FIG. 40.

The configuration of the power reception device 200 according to thisembodiment is not limited to the configuration shown in FIG. 40. Forexample, the power reception device 200 may further include the carriertransmission circuit 152 shown in FIG. 39. In the above-described case,the power reception device 200 has a function as the power transmissiondevice. The power reception device 200 may include, for example, a DSPand an audio output display including an amplifier or a speaker. In theabove-described case, the power reception device 200 can audibly reportan error, for example, by outputting an error sound from theabove-described audio output device in step S304 of FIG. 12. Forexample, the power reception device 200 may not include the operatingdevice 262 or the display device 264 shown in FIG. 40.

The configuration of the power reception device 200 will be describedwith reference back to FIG. 38. The storage section 202 is a storagemeans included in the power reception device 200. Here, examples of thestorage section 202 may be a magnetic recording medium such as a harddisk, and a nonvolatile memory such as a flash memory. The storagesection 202 stores, for example, power capability information, anapplication, or the like. Here, an example in which power capabilityinformation 230 is stored in the storage section 202 is shown in FIG.38.

The communication section 204 is a communication means included in thepower reception device 200, and functions to perform a wireless/wiredcommunication with an external device such as the power transmissiondevice 100. Here, the communication section 204, for example, whichcorresponds to the communication section 104 of the power transmissiondevice 100 can be configured.

The power reception section 206 is a power reception means included inthe power reception device 200, and functions to wirelessly receivepower transmitted from the power transmission device 100. Here, thepower reception section 206 receives the power by use of electromagneticinduction (the first transmission type), electric waves (the secondtransmission type), or electric- or magnetic-field resonance (the thirdor fourth transmission type).

The control section 208 is constituted, for example, by an MPU, a powermeasurement circuit, an integrated circuit into which a plurality ofcircuits are integrated to implement a control function, or the like,and functions to control the entire power reception device 200 orfunctions to perform various processing operations related to the powertransmission approach according to this embodiment described above inthe power reception device 200. An example of the process related to thepower transmission approach according to this embodiment in the powerreception device 200 may be a process related to the process(communication channel establishment process) of (1) shown in FIG. 3 or10, the process (power transmission process) of (3) shown in FIG. 21, orthe like.

The power reception device 200 can receive power transmitted from thepower transmission device 100 in a parameter of power based on parameterinformation, charge the received power to the internal power supply 268,or perform various processing operations using the received power, forexample, by the configuration shown in FIG. 38. Consequently, the powerreception device 200 can implement the power transmission system 1000capable of wirelessly transmitting power to the power reception device200 while preventing devices other than the power reception device 200from performing unauthorized power reception, for example, by theconfiguration as shown in FIG. 38.

As described above, the power transmission system 1000 according to thisembodiment has the power transmission device 100 and the power receptiondevice 200, and, for example, the process (communication channelestablishment process) of (1) to the process (power transmissionprocess) of (3) are performed, so that power is transmitted between thepower transmission device 100 and the power reception device 200. In thepower transmission system 1000, the transmission/reception of theparameter information in which a parameter of power is set is performedbetween the power transmission device 100 and the power reception device200 by the encrypted first communication channel formed by theabove-described process (communication channel establishment process) of(1). The power transmission device 100 transmits power using a parameterindicated by the transmitted parameter information. Here, the powertransmission device 100 acquires power capability information from thepower reception device 200 before the power transmission is performed,and sets parameter candidates of the power that does not exceed a powerreception capability indicated by the acquired power capabilityinformation. In the above-described process (power-parameter candidatedetermination process) of (2), the power transmission device 100 sets aparameter, at which a power transmission efficiency equal to or greaterthan a certain fixed level can be acquired in an actual environmentwhere the power is transmitted from among parameters of power that doesnot exceed the power reception capability indicated by the powercapability information acquired from the power reception device 200, asa parameter candidate of power. The power transmission device 100transmits the power by use of any one parameter among the set parametercandidates of the power. Consequently, the process (communicationchannel establishment process) of (1) to the process (power transmissionprocess) of (3) are performed, so that the power transmission device 100can transmit the power to the power reception device 200 using aparameter corresponding to an environment where the power istransmitted.

Because the power reception device 200 receives the parameterinformation via the first communication channel, the power receptiondevice 200 can efficiently receive the transmitted power on the basis ofthe parameter indicated by the parameter information even when the powertransmission device 100 transmits power using any one parameter amongthe parameter candidates of the power in a certain power transmissionperiod. Consequently, it is possible to further increase the powertransmission efficiency in the power transmission system 1000.

Therefore, the process (communication channel establishment process) of(1) to the process (power transmission process) of (3) are performed, sothat the power transmission system capable of reducing the powertransmission loss is implemented.

If the calculated first power transmission efficiency (the powertransmission efficiency in the power transmission period in which thepower has been transmitted) is less than the predetermined value (forexample, the lower limit of the set standard efficiency range), thepower transmission device 100 stops the power transmission. That is, thepower transmission device 100 can automatically stop the powertransmission if the transmitted power is received by a non-target deviceof the power transmission and the power transmitted by the powertransmission device 100 is not received normally in the power receptiondevice 200. Therefore, the power transmission device 100 stops the powertransmission if the calculated first power transmission efficiency isless than the predetermined value, thereby preventing the power frombeing continuously transmitted in a state in which the powertransmission loss is greater than a predetermined value. The powertransmission device 100 can prevent the power from being received by thenon-target device of the power transmission by stopping the powertransmission if the calculated first power transmission efficiency isless than the predetermined value.

The power transmission device 100 generates parameter informationexcluding an exclusion parameter or a non-use parameter for every powertransmission period, and transmits power on the basis of a parameterindicated by the parameter information in each power transmissionperiod. Therefore, because it is possible to transmit power on the basisof a parameter in which the power transmission efficiency is better, thepower transmission device 100 can prevent the power transmissionefficiency from being degraded in the power transmission for the powerreception device 200 (that is, can reduce the power transmission loss).

Further, the power transmission device 100 displays, for example, adisplay screen on which a power transmission condition as shown in FIG.18 or 19 is presented, and performs the process (power transmissionprocess) of (3) by determining that the presented power transmissioncondition has been approved when a power transmission start requesttransmitted from the power reception device 200 has been received.Consequently, in the power transmission system 1000, it is possible tocause the power transmission device 100 to start the transmission ofpower after the user of the power reception device 200 has pre-approvedthe presented power transmission condition.

Although the power transmission device 100 has been described above as acomponent constituting the power transmission system 1000 according tothis embodiment, this embodiment is not limited to the above-describedtype. This embodiment can be applied to various equipments capable oftransmitting power, for example, such as a vehicle as shown in FIG. 1, atable as shown in FIG. 2, a computer such as a personal computer (PC) orserver, a device having a reader/writer or a reader/writer function, amobile communication device such as a mobile phone or a personalhandy-phone system (PHS), a video/music player device (or video/musicrecorder/player device), a game machine, and the like.

Although the power reception device 200 has been described above as acomponent constituting the power transmission system according to thisembodiment, this embodiment is not limited to the above-described type.This embodiment can be applied to various equipments capable ofreceiving power, for example, such as a computer such as a PC or server,a mobile communication device such as a mobile phone, a video/musicplayer device (or video/music recorder/player device), a game machine, avehicle such as an electric vehicle (EV), and the like.

The power transmission system 1000 according to this embodiment can beapplied to various use cases in which power is transmitted, for example,as shown in FIG. 1 or 2.

(Program According to One Embodiment) [Program Related to PowerTransmission Device]

It is possible to transmit power to the power reception device 200 byuse of a parameter corresponding to an environment where the power istransmitted by a program for causing a computer to function as the powertransmission device according to this embodiment (for example, a programfor implementing the above-described process (communication channelestablishment process) of (1) to the above-described process (powertransmission process) of (3)). It is possible to implement the powertransmission system capable of reducing a power transmission loss by aprogram for causing the computer to function as the power transmissiondevice according to this embodiment.

[Program Related to Power Reception Device]

It is possible to implement the power transmission system capable ofreducing a power transmission loss by a program for causing a computerto function as the power reception device (for example, a program forimplementing a process related to the power transmission approachrelated to this embodiment in the power reception device 200).

It should be understood by those skilled in the art that variousmodifications, combinations, sub-combinations and alterations may occurdepending on design requirements and other factors insofar as they arewithin the scope of the appended claims or the equivalents thereof.

For example, the power transmission device according to this embodimentcan separately include the parameter information generation section 120,the communication control section 122, the power transmission controlsection 124, and the power transmission efficiency calculation section126 shown in FIG. 38 (for example, which can be respectively implementedby separate processing circuits).

For example, although the program (computer program) for causing thecomputer to function as the power transmission device provided accordingto this embodiment and the program (computer program) for causing thecomputer to function as the power reception device provided according tothis embodiment have been shown above in transitory embodiments,non-transitory storage media respectively storing the programs may befurther provided in this embodiment. Thus, in a transitory embodiment,the program is embodied in software or a propagating signal or wave. Ina non-transitory embodiment, the program is stored in a memory, such asa RAM.

The above-described configuration shows an example of this embodiment,and, of course, is included in a technical scope of the presentdisclosure.

It should be noted that the present disclosure can also take thefollowing configurations.

(1). A power transmission device comprising:

a first communication section for communicating with a power receptiondevice by an encrypted first communication channel;

a power transmission section for wirelessly transmitting power to thepower reception device;

a parameter information generation section for generating parameterinformation indicating a parameter of the power to be transmitted in apower transmission period for every power transmission period;

a communication control section for causing the first communicationsection to sequentially transmit the parameter information generated forevery power transmission period; and

a power transmission control section for causing the power transmissionsection to transmit the power on the basis of the parameter of the powerindicated by the parameter information sequentially transmitted to thepower reception device,

wherein the communication control section causes the first communicationsection to transmit a power capability information transmission requestfor causing the power reception device to transmit power capabilityinformation indicating capability regarding transmission/reception ofthe power before the power transmission section starts the transmissionof the power, and

wherein the parameter information generation section generates theparameter information on the basis of parameter candidates of the power,corresponding to an environment where the power is transmitted, set onthe basis of the power capability information transmitted from the powerreception device.

(2). The power transmission device according to (1), further comprising:

a power transmission efficiency calculation section for calculatingfirst power transmission efficiency indicating power transmissionefficiency in the power transmission period in which the power has beentransmitted on the basis of first power reception amount information,indicating a power reception amount for every parameter of the powerindicated by the parameter information in the power reception device,received by the first communication section,

wherein the power transmission control section causes the powertransmission section not to transmit the power if the calculated firstpower transmission efficiency is less than a predetermined value.

(3). The power transmission device according to (2),

wherein the power transmission efficiency calculation section calculatessecond power transmission efficiency indicating power transmissionefficiency in each power transmission period, andwherein the parameter information generation sectionsets a non-use parameter unused in the transmission of the power on thebasis of the parameter of the power indicated by the parameterinformation corresponding to one power transmission period if the secondpower transmission efficiency calculated for the one power transmissionperiod is less than a predetermined value, andgenerates parameter information excluding the set non-use parameter.

(4). The power transmission device according to (3),

wherein the parameter information generation section

sets the parameter of the power, indicated by the parameter informationcorresponding to the one power transmission period, to a non-usecandidate parameter serving as a candidate of the non-use parameter, ifthe second power transmission efficiency calculated for the one powertransmission period is less than a predetermined value, and

sets the parameter of the power, set to the non-use candidate parametera predetermined number of times in a fixed period, to the non-useparameter.

(5). The power transmission device according to (4), wherein theparameter information generation section periodically or aperiodicallyreleases the setting of the non-use parameter or the non-use candidateparameter.

(6). The power transmission device according to (1),

wherein the power transmission control section causes the powertransmission section to transmit the power on the basis of the parameterof the power that does not exceed power reception capability indicatedby the power capability information,

wherein the power transmission efficiency calculation section calculatesthird power transmission efficiencies, which are power transmissionefficiencies of parameters of the power, on the basis of second powerreception amount information, indicating a power reception amount forevery parameter of the power corresponding to the transmitted power inthe power reception device, received by the first communication section,and

wherein the parameter information generation section

sets a standard range of the power transmission efficiency on the basisof the calculated third power transmission efficiencies,

sets a parameter of the power corresponding to the third powertransmission efficiency outside the standard range to an exclusionparameter unsuitable for the transmission of the power if there is thethird power transmission efficiency outside the standard range among thecalculated third power transmission efficiencies, and

generates parameter information excluding the set exclusion parameter.

(7). The power transmission device according to (6),

wherein the power transmission control section calculates a powertransmission unit price corresponding to the set standard range of thepower transmission efficiency,

wherein the communication control section causes information indicatingthe calculated power transmission unit price to be transmitted to thepower reception device, and

wherein the parameter information generation section generates theparameter information if the first communication section has received apower transmission start request for requesting a start of thetransmission of the power transmitted from the power reception deviceaccording to the information indicating the power transmission unitprice.

(8). The power transmission device according to (1), further comprising:

a second communication section for communicating with the powerreception device in a non-contact type by a second communication channeldifferent from the first communication channel using a carrier of apredetermined frequency,

wherein the communication control section causes connection informationfor forming the encrypted first communication channel with the powerreception device to be transmitted to the power reception device via thesecond communication channel.

(9). The power transmission device according to (8),

wherein the communication control section causes the secondcommunication section to transmit the power capability informationtransmission request for causing the power reception device to transmitthe power capability information indicating the capability regarding thetransmission/reception of the power, and

wherein the parameter information generation section generates theparameter information including a parameter of the power that does notexceed power reception capability indicated by the power capabilityinformation on the basis of the power capability information transmittedfrom the power reception device according to the power capabilityinformation transmission request, received by the second communicationsection.

(10). The power transmission device according to (1), wherein theparameter information generation section generates the parameterinformation including a parameter of the power that does not exceedpower reception capability indicated by the power capabilityinformation.

(11). A power transmission method comprising:

transmitting a power capability information transmission request forcausing a power reception device to transmit power capabilityinformation indicating capability regarding transmission/reception ofthe power before transmission of power is started;

generating the parameter information, including a parameter of the powerfor every power transmission period on the basis of parameter candidatesof the power, corresponding to an environment where the power istransmitted, set on the basis of the power capability informationtransmitted from the power reception device;

sequentially transmitting the parameter information generated for everypower transmission period to the power reception device via an encryptedcommunication channel; and

wirelessly transmitting the power to the power reception device on thebasis of the parameter of the power indicated by the parameterinformation sequentially transmitted to the power reception device.

(12). A program for causing a computer to execute:

transmitting a power capability information transmission request forcausing a power reception device to transmit power capabilityinformation indicating capability regarding transmission/reception ofthe power before transmission of power is started;

generating the parameter information, including a parameter of the powerfor every power transmission period on the basis of parameter candidatesof the power, corresponding to an environment where the power istransmitted, set on the basis of the power capability informationtransmitted from the power reception device;

sequentially transmitting the parameter information generated for everypower transmission period to the power reception device via an encryptedcommunication channel; and

wirelessly transmitting the power to the power reception device on thebasis of the parameter of the power indicated by the parameterinformation sequentially transmitted to the power reception device.

(13). A power transmission system comprising:

a power transmission device for transmitting power; and

a power reception device for communicating with the power transmissiondevice and receiving the power transmitted from the power transmissiondevice,

wherein the power transmission device includes

a communication section for communicating with the power receptiondevice via an encrypted communication channel;

a power transmission section for wirelessly transmitting the power tothe power reception device;

a parameter information generation section for generating parameterinformation indicating a parameter of the power to be transmitted in apower transmission period for every power transmission period;

a communication control section for causing the communication section tosequentially transmit the parameter information generated for everypower transmission period; and

a power transmission control section for causing the power transmissionsection to transmit the power on the basis of the parameter of the powerindicated by the parameter information sequentially transmitted to thepower reception device,

wherein the communication control section causes the communicationsection to transmit a power capability information transmission requestfor causing the power reception device to transmit power capabilityinformation indicating capability regarding transmission/reception ofthe power before the power transmission section starts the transmissionof the power, and

wherein the parameter information generation section generates theparameter information on the basis of parameter candidates of the power,corresponding to an environment where the power is transmitted, set onthe basis of the power capability information transmitted from the powerreception device.

The above-described configuration shows an example of this embodiment,and, of course, is included in a technical scope of the presentdisclosure.

What is claimed is:
 1. A power transmission device, comprising: acommunication unit that transmits a power capability informationtransmission request via a communication channel and receives powercapability information in response to the power capability informationtransmission request; a processing unit configured to set a parameterbased on the power capability information; and a power transmission unitthat wirelessly transmits power using the parameter, wherein thecommunication unit transmits the power capability informationtransmission request before the power transmission unit wirelesslytransmits the power.
 2. The power transmission device according to claim1, wherein the power capability information indicates a transmissiontype and a parameter type.
 3. The power transmission device according toclaim 2, wherein the transmission type is defined by at least one of anelectromagnetic induction, electric waves, a magnetic-field resonance,and an electric-field resonance, and the power transmission unitwirelessly transmits the power using the at least one of theelectromagnetic induction, the electric waves, the magnetic-fieldresonance, and the electric-field resonance
 4. The power transmissiondevice according to claim 2, wherein the parameter type is defined by atleast one of a frequency, a voltage, and an azimuth angle, and the powertransmission unit wirelessly transmits the power using the at least oneof the frequency, the voltage, and the azimuth angle.
 5. The powertransmission device according to claim 2, further comprising: a storageunit that stores transmission power capability information, wherein theprocessing unit sets the parameter by comparing the parameter typeindicated by the received power capability information and a parametertype indicated by the transmission power capability information to addthe parameter type indicated by the received power capabilityinformation to a parameter type list.
 6. The power transmission deviceaccording to claim 2, wherein the processing unit is configured tocalculate a plurality of power transmission efficiencies for each of aplurality of parameters of the parameter type and to set a standardefficiency range based on a maximum power transmission efficiency of theplurality of power transmission efficiencies.
 7. The power transmissiondevice according to claim 1, wherein the communication channel isencrypted.
 8. The power transmission device according to claim 1,wherein the communication unit receives first power reception amountinformation for the parameter after transmitting the power, and theprocessing unit is configured to calculate a first power transmissionefficiency based on the first power reception amount information andcauses the power transmission unit not to transmit the power if thefirst power transmission efficiency is less than a predetermined value.9. The power transmission device according to claim 1, wherein thecommunication unit receives first power reception amount information forthe parameter after transmitting the power, and the processing unit isconfigured to calculate a second power transmission efficiency based onthe first power reception amount information and to generate parameterinformation excluding the parameter if the second power transmissionefficiency is less than a predetermined value.
 10. The powertransmission device according to claim 9, wherein, if the communicationunit receives additional first power reception amount information forthe parameter, the processing unit calculates an additional second powertransmission efficiency based on the additional first power receptionamount information, and, if the additional second power transmissionefficiency is less than the predetermined value a predetermined numberof times in a predetermined period corresponding to the first powerreception amount information and the additional first power receptionamount information, the processing unit excludes the parameter from theparameter information.
 11. The power transmission device according toclaim 10, wherein the processing unit periodically or aperiodicallyincludes the parameter in the parameter information after the processingunit has excluded the parameter from the parameter information.
 12. Thepower transmission device according to claim 1, wherein the parameterdoes not exceed a power reception capability indicated by the powercapability information, the communication unit transmits parameterinformation, the communication unit receives second power receptionamount information after the power transmission unit wirelesslytransmits the power, and the processing unit is configured to calculatea plurality of third power transmission efficiencies of a plurality ofparameters based on the second power reception amount information, toset a standard range based on the plurality of third power transmissionefficiencies, and to exclude one of the plurality of parameters from theparameter information if the third power transmission efficiency of theone of the plurality of parameters is outside the standard range. 13.The power transmission device according to claim 12, wherein theprocessing unit is configured to calculate a power transmission unitprice corresponding to the standard range, the communication unittransmits information indicating the power transmission unit price, andthe power transmission unit wirelessly transmits the power using theparameter if the communication unit receives a power transmission startrequest in response to the information indicating the power transmissionunit price.
 14. The power transmission device according to claim 12,wherein, if the third power transmission efficiency of the one of theplurality of parameters is outside the standard range, the powertransmission unit stops wirelessly transmitting the power.
 15. The powertransmission device according to claim 1, wherein the communication unittransmits or receives connection information for forming thecommunication channel via a non-contact communication using a carrier ofa predetermined frequency.
 16. The power transmission device accordingto claim 15, wherein the communication unit transmits the powercapability information transmission request via the non-contactcommunication, the communication unit receives the power capabilityinformation via the non-contact communication, and the parameter doesnot exceed a power reception capability indicated by the powercapability information.
 17. The power transmission device according toclaim 1, wherein the processing unit is configured to generate parameterinformation indicating the parameter, based on parameter candidates ofthe power, corresponding to an environment where the power istransmitted, set on the basis of the power capability information.
 18. Apower transmission method, comprising: transmitting a power capabilityinformation transmission request via a communication channel; receivingpower capability information in response to the power capabilityinformation transmission request; setting a parameter based on the powercapability information; and wirelessly transmitting power using theparameter, wherein the transmitting the power capability informationtransmission request is performed before the wirelessly transmitting thepower.
 19. A program for causing a computer to execute: transmitting apower capability information transmission request via a communicationchannel; receiving power capability information in response to the powercapability information transmission request; setting a parameter basedon the power capability information; and wirelessly transmitting powerusing the parameter, wherein the transmitting the power capabilityinformation transmission request is performed before the wirelesslytransmitting the power.
 20. A power reception device, comprising: astorage unit that stores power capability information; a communicationunit that receives a power capability information transmission requestvia a communication channel, transmits the power capability informationin response to the power capability information transmission request,and receives parameter information based on the power capabilityinformation; and a power reception unit that wirelessly receives powerusing a parameter indicated by the parameter information, wherein thecommunication unit receives the power capability informationtransmission request before the power reception unit wirelessly receivesthe power.